Network Support I
At the request of another discord user, reposting the information here for further discussion and archival. For context, I'm an accomplished 3gun shooter, reticle designer for Atibal Optics, and engineer. The below is based off of my experience and understanding of red dots and their variants in a competition context. Please don't get upset by any jokes or references, this is copied and pasted from the larger conversation.
So, Holosun 403 vs 503 vs 515, reticles, and reticle colors. The primary difference between the 4xx and 5xx is the multi reticle. Frankly, there is zero reason to get a 4xx series holosun unless you're being cheap. The 65moa circle dot is a significant advantage for all of the same reasons it's loved in eotechs. 503 vs 515 is where things get a little screwy. Both the 403 and 503 have a garbage tall mount. It's simple extruded aluminum, and the cheapest possible crossbolt. The bolt will strip out or break eventually, unless you buy guns just to store them in a safe. The 515 mount looks stronger (no hands on experience personally), and also comes with lens covers and a ARD for street cred at milsim west. That being said, Geissele, ADM, etc. all have mounts available in the $50-$75 range, so if you catch the right sale you're still sub $300 for a 503GU.
Dot vs CircleDot vs ACSS The number one reason to get a Holosun over another option is the circle dot reticle. It gives you the ability to intuitively range and holdover for up close and personal shooting, and you can turn the ring off for precise or low light use. Best of both worlds. ACSS as a general family of reticles is designed for the crayon connoisseurs, in that it dumbs things down as much as possible for uneducated shooters to work as a crutch. Perfect for the guys who consider 8moa prone to be good shooting, and think volley fire at 500 yards is a valid tactic in the boogaloo. Don't forget your matching magnifier, because those BDC dots are a blur with any vision imperfection or astigmatism. There's a reason no one uses it in a competitive context, and instead favor etched prisms or ballistic turret dots.
Reticle colors: Red we all know and love, but the original reason it was selected was due to power draw vs apparent brightness. Red is simply the most efficient of the led colors. Lucky coincidence is that red also contrasts well in almost all conditions, and has less eye strain after extended use in low light. Green is the new hotness everyone wants. I'm not sure why it became a thing in the first place, but I suspect it's due in part to younger gun owners wanting nicer optics but with the same green illumination as their utg/sightmark/etc discount optics they started with, or to match the reticle they used all the time in COD. Green lasers/emitters/leds are way less efficient than red, but the eye does respond better to shades of green better than red or blue. In urban areas it's effectively the same as red in use, but in rural greens it's easy to lose that dot in foliage/trees unless you crank the brightness. Gold. This one I don't understand at all, other than being able to claim "we did it first". Maybe someone else has a better understanding than I do.
Offset dots and LPVO's. I'm not a copper, swat dude, frogman, or spook, so I can't say what works best for their jobs. In a competition context, you see very few open division shooters that don't run an offset dot, or have an offset dot and choose not to use it up close. The biggest factor in that is reticle design/brightness. Even at 1x, a good dot blows the Kahles 3GR brightness out of the water. It's a damn good intermediate distance optic, but it simply can't beat the brightness of a red dot in direct sun/sand environments. If speed is the name of the game, I want enough brightness that I can't miss the dot. The other part with reticles is the 65moa Circle Dot wins at bad breath distances every time compared to dot only, for all the reasons I listed above, especially when it's bright enough for the conditions. I can't get the best of everything in one scope reticle, so offset buys me capability I wouldn't have otherwise. The last part is that ad much as we want to say LPVO's are juz as gud as a red dot, there's a perceptible difference even if you're comparing 1x to 1x. It may be small, but I'll take any advantage I can get, especially if the weight penalty is only 6 ounces.