To start off i just want to say i love this stock so far. I like the colour the way it feels on my shoulder, how structurally sound it is, and how it accents my gun.
However, I purchased an Ares M4 CQB (S-Class), and this stock is a very very tight fit. I'm have and extremely hard time moving it between the different positions. So far i am using a flat head screw driver to pry down the adjustment pin and then move the stock.
Overall I do love the stock, and I think after I work it some more it will loosen up.