I'm turning into a bit of a 1911-aholic, I've got 3 of them. A Colt 1911 made in 1914, a Springfield 1911A1 Mil Spec, and an AO 1911A1 pre-Khar. Out of the 3 of them using the same mags, I have found the AO to be the most reliable, the Springfield to be the most accurate and the Colt to have the nicest finish.
I have tried different mags, a polished feed ramp, and taking out the shokbuff, all to still have my Springfield fail to lock into battery from time to time. I have recently read up on tuning the extractor and have tweaked it a bit to try and solve the problem but haven't had any range time due to work.
Having said all that, the AO went through 200 rounds without a hiccup when I first got it. It's not tuned like my Springfield but it sure does go bang and feed properly following a pull on the trigger. I just put a full length guide rod in the AO but more since I found it a pain to get the barrel bushing turned while stripping it than anything to do with reliability.
I like mine but there are some bad reviews out there on the AO stuff.