If you do use the Search feature you can find a lot of threads on the very subject.
I have an AztekA430. It seemed to work OK the few times I used it, and any problems that I had, I ascribed to my own lack of skill rather than any deficiency on the part of the Aztek. Then one day it stopped working, this despite my having rigorously followed all cleaning and care instructions, so I sent it back to Testor's for warranty replacement.
During the three-week reapir turnaround, I picked up a Badger 200NH which is a single action variant of their Anthem 155 double action model. I found the Badger far easier to use, (although that may be due to it beaing single action). I found that cleanup was no more difficult than with the Aztek and in many respects the Badger is actually easier to clean up. The paint quality in terms of overall paint finish and fine line control on the Badger was always as good or better than that of the Aztek. After my Aztek was returned, I connected it to my compressor just once just to verify that it was indeed fixed (or replaced, I don't know which), but I have never used it since. During the interveing years, the Badger has proven to be more reliable as well.
A year or two later, I started using acrylics paints, and decided to get a second brush, and for that I opted for the venerable Paasche H. I think all my comments about the Badger compared to the Aztek apply equally with respect to the Paasche compared to the Aztek.
Reliablity issues aside, Azteks are usually quite a bit more money than conventional airbrushes and don't really provide and real advantage. Their main marketing line is that they are easier to clean, which is total rubbish. Ultimately, I do feel that my original decision to buy an Aztek was indeed a mistake.
On the other hand, since you have one, and you like it, use it and enjoy it. Until it dies, and there's no guarantee that it will do so, there's no reason to switch. But if it does die, remember that there are a lot of better alternatives out there.
Andy