I have a 16" ASA. I have not had a single problem with it. I bought it back in 1999. Back then from what I understand they were using LMT receivers, and I understand those to be some of the better ones. From what I heard lately, mostly from the web forums (so it must be true) there quality is not what it used to be. I do have a friend that bought a 16" m-4 style from them about a year ago and have not heard him complain about it. FWIW after the ban ended I went with a DPMS 16" M-4 no-ban config for a couple reasons.
1.) DPMS is not getting the bad rap that ASA is lately.
2.) Price - I have $606 in it including shipping. Including a 4 position stock and a chromed bolt carrier.
I am local to Arizona where ASA is. They offer a lifetime warrenty on thier rifles, so it wouldn't be that much of an issue for me if I did have a problem. But, like I said I haven't had any.
Just my $.02
-J-