I just finished my build of a PSA AR15 in 9mm couple of weeks back. Built this with all PSA parts on a dedicated lower that uses Glock mags. Only thing I don't like is the lack of a last shot hold open, other than that, it's 100%. Even the factory sight was within 2 clicks of zero out of the box. I've fired about 600 rounds so far and not 1 problem. My reloads run fine, if they ran in a pistol, they will run in this. With a red dot sight, very accurate up to the 100 yards I've shot at so far. Reason I started this project is that a 22 LR around here is 8-10 cents a shot when you can find them. I load cast boolit 9mm rounds for 4-5 cents a shot. Fine little rifle just for the grandkids to plink with. Costs =
the assembled lower group that uses glock mags. = $250 or so
The 9mm upper assembly with the charging handle and bolt = $350
Mags and a cheap Bushnell red dot = $100+
Total = $700 range
A Colt made 9mm AR 15 = about $1100 base price
PSA units show good quality and work well, happy with the end result of my project.