I have used the BFG VCAS (padded and un-padded, sewn-in QD and non, "Victory" version and original), the VTAC (padded and non), the SOB (QD swivels), the Magpul MS4, and the Boonie Packer 2 PT they are all derived from, plus a bunch of older 1 point stuff that isn't even really worth discussing. I've used them on ARs and AKs and that's about it. I attach all of them in front of my weak hand on my weak side, and at the heel of the stock on my strong side. A couple of things I have found...
I don't like padding. Good, stiff, webbing like the VCAS more than makes up for padding, and the padding just adds bulk.
I don't like free-running tails. The VTAC now has a way to secure it (I think) and the SOB definitely has a way to secure it. Not ideal, but better than having it flop around.
I do prefer at least some amount of short tail, that doesn't get longer when I pull it, attached to the adjustment slider.
I like sewn-in, QD sockets, and not really any other attachment method. I don't want to deal with sliders just to attach a QD that I'm never going to take off. On the front they get in the way of my support hand and at the rear they sit funny on my collarbone or shoulder.
I like a sling with the flexibility to allow me to carry it across my front or across my back, muzzle-down in both instances.
I like a sling with the flexibility to allow me to change it over to a 1-point if I want to (this is not a deal breaker for me).
I've had my BFG Vickers sling since 2009 when I got it for Afghanistan. It has been on my LE rifle ever since then and is still running strong. Although, I think I had to replace one of the old style plastic pieces since one cracked, but such is life. I have zero intention of getting rid of this thing!
MS1 in regular 2-point configuration, of course. If you haven't tried the new slings based on the MS1 slider (the new MS3s and MS4 all use it now) you should give it a look. No loops, tails, or tag ends to flop around, fast, secure adjustments, durable as heck, and the padded variant uses a variable-width tubular webbing which means there's nothing extra sewn on or any seams...it just transitions to the padded section smoothly.
Old thread but I'll throw in my $.2. Big fan of the Urban ERT slings. Running their RUSH two-point/single-point system on my personal rifle and on my patrol rifle. Love the ability to rapidly change from a two point to a single point style sling in less than a second. Thick seatbelt material is comfortable and Distributes weight nicely. Quick adjustment of the overall length is slick and there is a quick detach if SHTF.
Although I rarely find myself running my rifle in a single point configuration anymore I always run the shotgun in a single point config. Running the pump gun for breaching duties or less-lethal I don't have to contend with the sling and short stroke the action. Brings up another point, I run the same sling on both the the rifle and shotgun in my prowl, just swap it over to the pump gun when I need it.
I've tried VTAC, Magpul and MS4. I like all of them, but the SOB is my favorite. The MS4 is hard to cinch down tight and keep that way, but I like the width and stiffness, and the ability to have a 1 point sling for the 1% of time that I think a 1 point sling is a good idea is also a nice, if unneeded feature. The VTAC is a great sling for all the reasons that the SOB sling is a great sling, only the SOB is better, because the buckle stays in the same place all the time, and is faster to get to. I have been trying Pat McNamara's Sling Ding for a while, too, and like it. Very handy for improvised support positions.
I prefer the seirra tac padded sling for my 14.5 and longer guns. For a SBR I like the non padded Vickers sling. I ran a padded vtac for a while on my M16 and while it's still a good sling, there is just too much extra material hanging off of it compared to newer sling designs.