Well I got home and took a look, the barrel hood was much tighter no play at all in battery. They replaced the extractor, the slide stop and barrel link.
They did not clean it after their test fire though!
I put about 200 rounds through it and it worked very well, only three failure to feeds and they were the chip Mccormick mags fault. Seems the mag follower, is tilting foreward and letting the nose of the round push down so it wont go up the feed ramp.
I wonder if Brownells will take them back?