Comparison: Steiner P4Xi 1-4x vs. Vortex Viper PST Gen II 1-6x

I originally posted this on the M4C forums but I saw that others, specifically @Mr Hardy, had recently asked about it here, so I am cross-posting. The reason for the comparison is due to recentl price increases on the Steiner and price drops on the Vortex, which has brought these two optics much closer together in price point than they were previously. A year ago, the P4Xi was available for around $450 with regularity and the PST was sticking close to the $700 mark. As I typed the original comparison earlier this year, both were consistently available for around $550.

Quick background: I have a sample size of one P4Xi and two PST Gen IIs. My examples are certainly not safe queens, but I do not intentionally abuse them (aka "torture test") either. All three have all been banged around in my 4x4, run through training courses, exposed to the elements for days at a time, and have seen plenty of vibration, dirt exposure, hard knocks, and huge temperature and elevation fluctuations for me to formulate solid opinions of each. I've owned the P4Xi for about 2 years and have 7,500+ rounds behind it and has been to one 2-gun match and two carbine classes as of the time of posting. The oldest PST Gen II is less than a year old with 4,400+ rounds behind it at the time of posting and has been through 4 carbine classes.

Objective Observations:
Size & Weight:
The PST is only 1/2" longer than the P4Xi, but in reality it's much bulkier and larger in both feel and appearance. The PST is approximately 5oz heavier as well. The Steiner is far more streamlined overall.
Throw Lever: The P4Xi Model 5202 I purchased included an excellent throw lever that integrates seamlessly within a groove in the magnification ring and matches the scalloped texture of the scope as well. I had to purchase the Vortex SV-5 SwitchView lever separately which retail for about $45-$60. The SV-5 does not integrate into the magnification ring of the PST but rather just sits on top of it and is held in place by friction, on par with most aftermarket type offerings. I've not had any issues with either but the Steiner is clearly the more well thought out of the two.
Sight Picture: The view through the P4Xi is a bit flatter than the PST at 1x, and is about as close to "true 1x" as any other LPVO I've spent much time behind. The PST, although it is very close to true 1x, does have an ever-so-slight fisheye effect at 1x indicating slight magnification present. However, the PST has less of the ocular housing ring visible while looking through the scope than the P4Xi. Despite the Steiner being closer to true 1x, I find the Vortex is a bit more "red dot like" with a "larger" image for lack of a better term thanks to the thinner scope shadow around the sight picture (by scope shadow, I'm not referring to incorrect head placement but rather the visual appearance of the outside edges of the ocular bell itself in your field of view). These visible edges are not as slim as in the Razor, for example, but it is still markedly better than the P4Xi in that way.
Eye Relief: Eye relief distance is roughly the same between the two, and both are fairly consistent throughout the entire magnification range. A slight edge may go to the PST in that regard, but it's not a distinct advantage over the P4Xi.
Eye Box: The PST has a more forgiving eyebox across the entire magnification range, particularly at 1x. The P4Xi's eyebox is a bit tighter but with proper set-up and repetition it has been of little consequence to me except when shooting from very unconventional shooting positions.
FOV: The PST has a slightly wider field of view from 1x-4x. Obviously it has a narrower field of view than the P4Xi at maximum power where ranging and holdovers are accurate because of the higher magnification.
Reticles: Both optics are SFP. The P4Xi provides very usable BDC holdovers. The PST provides very usable Mil/MOA reference points for ranging, holdovers and windage compensation depending on model. Using the scope as a red dot, both reticles are functionally identical in my opinion. The crosshairs on the P4Xi are slightly thicker than the PST's in the center but are still fine enough for precise shot placement.
Dot Brightness: Both optics feature a single daylight bright red dot that illuminates in the center of the reticles. The P4Xi features much broader adjustment range that goes from so dim it isn't visible to the naked eye to "Aimpoint-bright." The PST starts brighter than the P4Xi but at the very top end they are both similar. If I had to say one is any brighter than the other at maximum setting, I'd give the nod to the Steiner. For those with astigmatism such as myself, both optics illuminated center dot may be distorted, but will still appear sharper than a red dot thanks to the magnified optic's adjustable diopter.
Battery Life: The PST appears to have better battery life thus far but it's not a fair assessment since I have not owned either of the PSTs long enough to run through a full battery. I am on my 3rd battery for the P4Xi and the original battery on my oldest Vortex is still going strong. They both use industry standard CR2032 lithium. Neither appear, at this point, to self-drain when powered off.
Glass: Resolution and color fidelity in both are excellent given the mid-$500 price point, with a slight edge going to the German Schott glass in the P4Xi simply because it's a bit clearer edge-to-edge. In terms of light transmission and overall clarity they are functionally similar enough that I don't have a preference towards either one. They have both been through low-light / no-light carbine classes and performed better than I expected.
Turrets: The windage and elevation turrets on both are mediocre at best. The low, wide dials on the PST look better and feature slightly more well defined clicks than the Steiner, but one of my two is actually a lot better than the other so there is some inconsistency from scope-to-scope in the Vortexes. Both the P4Xi and PST are pretty spongy overall. My P4Xi's clicks are very poorly defined and not audible. The zero reset on the Vortex is easier/more convenient than the Steiner but assuming most will never even use this feature, it's kind of a moot point. The PST's turrets are indeed better than the P4Xi's, but they both leave a lot to be desired.
Rheostats: Both feature off-positions between each intensity setting which is very nice, but the Steiner's dial is again very mushy whereas the PST's has a definitive tactile and audible clicks. The Steiner does, however, offer a broader range of adjustability from what I presume is NV compatible (so dim it's not visible to naked eye) to Aimpoint-like brightness with a fresh battery as noted previously. Despite the PST's rheostat being "nicer", I give the nod to the Steiner for the larger range of adjustment capable of being more finely tuned to present lighting conditions.

Subjective Notes:
Finish & Feel:
Everything about the Vortex feels more rugged. The controls are firmer, there is no slop or play in any of the dials and adjusting the eyepiece requires a concerted effort whereas the Steiner's is so easy to turn it often comes out of adjustment on its own, making witness marking an absolute necessity. Visually, the anodizing on the P4Xi has held up better over time. My older PST already looks more "well-used" than it is due to the superficial scratches and dings all over it, whereas the only areas on the P4Xi with any marks are on the throw lever and turret caps. I attribute this largely to the shape and bulk of the Vortex, but the finish on the Steiner may just be superior as well. However, the build quality and overall mechanics of the PST gives the impression that the it is more robust.
Red Dots: To my eyes, the PST provides better defined dot than the P4Xi. I have observed no functional difference between the two in actual shooting, but if a blurry dot is distracting to you, you may prefer the PST. This is highly dependent on your eyes, corrective lenses, etc. but is worth noting.
Magnification: Obviously the trend lately has been higher and higher magnification ranges up to and including 1-8x and 1-10x optics. Personally, I have no issue taking the P4Xi to 500 yards, although group sizes do suffer past 200 compared to the 6x PST. For 200 yards and in, I have no preference either way. That said, I've observed no detriment to having the extra magnification in an SFP optic since holdovers, etc. are only really applicable beyond 200 yards with a 50/200 zero anyways. Therefore, the PST is more versatile in regards to precision and PID at moderate ranges, but that benefit is highly dependent on application. Both will make IPSC B/C zone hits reliably possible out to and potentially beyond the maximum effective range of a 5.56 carbine.
Weight: 5oz difference will be insignificant to most. From a bench or shooting drills for an hour or two, it makes no difference. After running and gunning for 14 hours straight in a day/night training course, hunting all day or hiking with my rifle, I can absolutely feel the difference as my arms and shoulders fatigue more rapidly with the PST equipped versus the Steiner. Yes, I'm out of shape and I should lift more, but the fact remains that everyone will fatigue at some point and a heavier rifle is going to wear you out faster than a lighter one will.
Reliability: I've had no issues with either of my Vortexes, but again, I haven't had them long either. My P4Xi on the other hand, had a nitrogen leak from one of the seals in the ocular bell after a few nights below freezing, but so far it has not compromised the function of the scope. I am keeping a close eye on it and have moved it to a backup gun in the meantime. Also, the magnification ring on the P4Xi has and developed a very spongy feeling rather than a solid stop at both maximum and minimum magnification settings which, again, has not affected function, but is possibly indicative of a less durable design. Finally, the diopter on the P4Xi has loosened considerably as mentioned earlier and it just takes the slightest bit of contact to move it, so it is frequently coming out of adjustment. I've resorted to using thick blots of the enamel paint I use for witness marking to try to lock it into place a bit which works for a while, but the paint fails eventually and it moves on me again after a while.
Warranty: Hands down, there's no doubt Vortex wins here. I haven't had to use the warranty on any of my Vortex optics to know that because their stellar reputation precedes them. Meanwhile, when I contacted Steiner's customer service about the faulty seal on my P4Xi, they were generally unhelpful and didn't inspire any confidence whatsoever in them handling it so I decided to just keep it and see what happens long-term. Steiner's social media people also left a bad taste in my mouth with their responses to posts on Instagram and using my photos for marketing purposes without giving any permission or photo credit given.

At the end of the day, they are both very good lower middle class optics and I wouldn't hesitate to run either one. Overall, I feel that the PST is a better built and more versatile optic so it would be my choice for a general purpose go-to rifle unless size/weight is a primary consideration and ranges aren't expected to frequently exceed 200 yards, in which case the P4Xi would be my choice for that application.

Reticle Comparisons:
With / without illumination, PST left, P4Xi right.
NOTE: To my naked eye, the dot intensity settings seemed comparable and appropriate for the lighting conditions. The camera had other ideas. In reality, the P4Xi dot seemed larger and brighter to me than the camera shows, and likewise, the dot on the PST appears to be massive but that is absolutely not the case in reality.

Recent photos with PST in the foreground and P4Xi in the background, both mounted in ADM Recon-H mounts. The PST Gen II has become the primary optic on my go-to carbine:

PST Gen II at a recent no-light / low light carbine course. It performed admirably. RDS/holographics still reign as king of the night by nature of the design, but I've had no issues acquiring a sight picture, identifying and engaging targets at zero to fifty yards with the PST or P4Xi behind a Surefire M600DF or Streamlight HL-X.

Thoughtfully written comparison. Good stuff!
Thank you, it's hard to differentiate between factual and opinionated information when writing a review so I tried my best to keep a hard line between the two to avoid any bias, even though I own, use and enjoy both optics.