I don't like metal fasteners or quick adjusts on my sling. I have the lead faucet and like it a lot. I would also consider the VTAC PES ULTRA LIGHT SLING W/PLASTIC BUCKLE if you wanted extra padding or the BFG GMT sling if you want no padding. I like the Lead Faucet as a compromise. the wider neck portion is very comfortable without adding any bulk.
The SOB sling looks pretty slick. I haven't used it but the idea that the quick adjust is in the front is very interesting.
The VCAS is good but kind of thick and bulky, I like the RB1 sling personally.
I like the VTAC over any of the other "quick adjust" slings due to the free tail allowing me to go tighter than VCAS usually allows. Also the VTAC adjusts quicker it seems.
I, too, prefer the longer adjustment range of the Viking Tactics sling. I'm less keen on the release though, as sometimes I find myself fumbling with it. I would like to find something with a similar adjustment range of the VTAC sling but with a more positive release, but so far haven't. (Not that I've tried a bunch of different slings - that would get quite expensive quite soon, and for not that much gain.)
IDPA SSP classification: Sharpshooter
F.A.S.T. classification: Intermediate