This is a pretty great take, and I endorse it wholeheartedly. The UBR is a pig on AR-15s, but balances much better on the heavier AR-308s. I also like the MOE fixed carbine stock, too - I know some people find it too short, but it's cheap and solid.Have a battlelink, really light, balances tiny SBR barrels and lightweight builds well, locks up tight, and slim profile.
MOE SL are my go-to stock for most carbines, slim, simple, and comfortable.
The ACS series are too bulky/heavy IMO, and in the longer/ heavier rifles where that wouldn't be a big deal, I like a heavier stock with a fixed cheek peice anyway.
For fixed stocks, it
's hard to neat the MOE rifle stock, slim, comfortable, and well built, have had 0 problems on a 3 gun rifle I built with one several years ago, only downside is you need to add expensive QD sockets if you want to run a QD sling.
Have a UBR2 that I really like, it looks awesome, locks up like a fixed stock, and is A5 compatible. It is awesome for balancing heavier SPR or AR10s where you want an adjustable stock, and something a bit simpler and more mobile than the PRS, but need it to be solid and balance out a heavy barrel. It's pricey, but worth it, allows A5 buffers in AR15s, or standard buffers in AR10s.
IMHO, the stock I'd choose is probably going to mostly be driven by what's going on with the front-end of the gun in terms of weight. If you're running a pencil barrel with no can, I'd probably choose an MFT Minimalist stock. If it's a chunkier profile barrel like an HBAR and/or there's a heavy can on the end, ACS-L probably makes sense. And, if it's something in between, maybe a CTR.