Its an A1 stock, not much to mess up.
I got mine used, and it works great, and feels solid. No wiggle.
However, the butt plate (term?) does not fit the actual stock that well. There is a bit of "overlap". Nothing that will break the function though.
For what it is worth, my older DPMS A2 stock had the same issue with the butt plate.
The inside of the stock/trap door is empty, my DPMS A2 had some white lining, which made the stock a lot heavier.
But aside from that, it is a solid stock. I asked some people online before I bought it, and they all said that the Cav arms stock worked great.
For $35, it gets the job done.