Great, except for a couple unacceptable flaws - Magpul ACS Mil-Spec Carbine Stock

First the good. Very comfortable cheek rest, easy on/easy off, multiple battery compartments, price is lower than closest competitor (VLTOR)

The biggest flaw for me is idiotic design of the release mechanism for sliding and removing the stock. I need to be able to remove and install the stock easily with no tools. This stock requires a little plastic 5.56 dummy round to retract the adjuster pin far enough to install and remove the stock from the buffer tube. Before you say just use a straight rod, the hole in the pin into which the tool/bullet inserts is in the opposite side of the pin and a straight rod bottoms out on the near side of the pin before the pin retracts far enough to get it on/off the buffer tube. The neck of the bullet shell is actually needed to lift the pivot point high enough to keep the pin from bottoming on the bullet section out before release. Problem is the spring on the pin is so stiff the plastic bullet is too soft to retract the pin high enough before it slips or breaks off the tip. Use a real bullet you say? The spring is so stiff it actually dislodges and cants the bullet in the case before the pin retracts far enough. Seriously, every other AR adjustable stock mfr uses a similar tooless release.

The so called locking mechanism for just adjusting the position on the buffer tube isn't a locking mechanism at all. When you press the adjuster lever it unlocks the locking mechanism and the stock can be ajusted. How is this a lock?

Finally, the stock doesn't have any holes for QD swivel mounts. They include a screw mounted cylinder which can be mounted in a hole right behind the slide release lever, but you have to choose right or left side, no switching. I also don't know how strong it is, but maybe that's a plus if your rifle gets snagged on something... breaking away might save you from being dragged. The only other strap attachment is the fixed strap slot on the bottom of the stock. I guess this is OK when slung over your back, but if you want to carry in front, it causes your rifle to flip inverted.