I have two of them (.45 & .38 Super) and they are an exceptional value. Like MassMark says, the .38 Super shoots good out of the box, but one of the things on my list is to upgrade some of the internals, sights, and possibly the barrel.
The big difference between the RIA and the AO is that you can more easily upgrade and fix the RIA. The tolerances (hole alignment, sear angles, etc) are much better on the RIA than on the AO. I local gunsmith I know discourages people from trying to upgrade their AOs because they're a PITA to work on.
You know on some parts where it says "some fitting may be required"? Change "some" to "tons" when it's an AO.