I've never liked adjustable AR stocks for precision shooting, even the ones that lock, as they usually still have some movement in them after a while. Getting the correct cheek height is also very important for precision shooting. Going from a little strain in your neck to none is still a noticeable difference. Coming from a B5 SOPMOD on this build to this PRS Lite is a night a day difference (with respect to precision shooting that is)
I've never had a problem with adjustable stocks, but it's a personal thing, everyone is different. On adjustable cheek pieces, I've always felt that if I can shoot irons without a cheek riser and no neck strain, a magnified optic shouldn't pose much of an issue either. Cowitness height is about ~2.6" with irons and red dots, so when I move to a magnified optic that has a scope height of 2.6-ish", what do I need a cheek riser for? That's where my headspace is at but maybe I can get one of my editors to foot the bill for a review on one of these.