I have an ACS, an STR, the standard collapsible, and an A2. Four different rifles. The STR is my fav, but the ACS has a pocket that will carry the coin batteries for the scope on that gun, the A2 is on a full length rifle, and the standard collapsible is on a carbine gas action strictly for size and weight. The "right" stock seems to depend on the rest of the rifle and its purpose, I've swapped uppers and put the ASC on my rifle but it just doesn't seem to fit as well as the A2. So look hard at your piece, scratch your head and in this market you can always sell your mistakes.