I have been with auction ads since it came out. From June till today it has been a tough go. Reporting is broken, several times a week you have irrelevant ads or no ads. Ctr has fallen through the floor in this time too. Even though I greatly prefer building ads in AA compared to CJ I am replacing most all of my AA ads with CJ.
AA is much easier to use but CJ works much better and you actually can do more with it if you take the time to.
While AA does have it's fair share of issues, I'm still able to make a pretty penny or two from them. I also use CJ as well on a few of my sites since I've found a program called PHPBay - on the sites that I've used both AA along with CJ/phpbay I've been very happy with. Don't limit yourself to just one thing, try them both and try them together and see which works best for you.