The ACS is nice for cheek weild and extra storage. I stow my electronic ear plugs in it and batteries if I think the foxpro is gonna give out on me real soon. The real question is whether you are gonna go with mil-spec or commercial receiver extension tubes? Because I promise, once you buy a magpul stock whether it be MOE,CTR, or any other, you will buy another and another after that. I have two ACS stocks and am looking at buying a UBR very soon. Pick a tube you like and try to stick with it for all your AR's so they dont get mixed up and not fit right. I have all mil-spec tubes, so I buy all my stocks mil-spec. Pretty soon, you will be swappin stocks like women switch purses.