I just finished most of the lower build and had very few problems, but I do have a question.
First, just a comment. I picked up a Yellow Tavern small parts kit when I got the lower, and I have to say that they give you just aboout everything, except extra $^! rear takedown detent, which was the first thing I lost. So the extra $18 didn't help me at all, which was a little frustrating. I probably missed that tip in a dozen places, but figured I'd mention it.
My question is that the lower assembly instructions on this site state pretty clearly that you ought to get the front pivot pin right the first time, because it's difficult to remove it. I just know I'm missing something obvious, but don't I need to pull this pin at least partially out to pin the upper and lower together? I may not have gotten this right, because the pin is IN there, and not moving. Same question on the rear pin, although that's not an issue until I receive my replacement detent.
Other than that, the instructions on the site, and tips, were excellent and made the process go pretty smoothly. Thanks, from a new guy!