I used it my last build. I liked it alot and it works well as a finished product but I did have to smoth out the bolt catch so it would go into the receiver. It was obviously flawed which is something I think should not have been there for the price but once installed I do enjoy it very much and it's breaking in very smooth and crisp.
oh yeah make sure to put just a drop of blue locktite on the ambi safety screw. I locktited all of my screws but I have a really good set of alens and a small torch also.