I had some really good luck with them, I guess. I did have a problem with my trigger pins not wanting to fit, but I chucked them up in the drill and took a little light emrey cloth to them and they fit really nice now. I called Model one to tell them about the problem and they sent me an complete pin, detent and spring kit, I got it a day and a half later. I suspose I will eventually build more AR's and try other companies, but for now I am very happy with the way the gun turned out.