The problem is you don't know what you like until it's too late. Following are my experiences with an Aztec that I posted some time ago and a follow-up on my Omni experiences.
I purchased an Aztec A470 about a year and a half ago on the recommendation of my LHS. I was getting back into modeling after a long, long time away and had never used an AB.
I fought the Aztec all the way. The nozzles were a pain – always clogging. Soaking was only marginally successful – and I pulled the nozzle immediately after completing a job. Sometimes I changed nozzles several times during a session. I almost always had to pull the needle out and clean it and the spring. The caveat is I use Tamiya flat acrylics exclusively – thinned 50%. This could have been a factor?
But, the biggest problem was it never worked in double action mode. It started shooting paint as soon as the trigger was depressed, regardless of the adjustment setting, the air pressure setting or the nozzle being used. A warranty replacement still didn’t fix the problem.
I finally solved the problem a couple of months ago. I purchased an Omni 6000, so I could use my Aztec cups. In my opinion, there is no comparison between the Azrtec and the Omni. And, I tried long and hard to make the Aztec work.....
A further caveat. I would think seriously about buying an Omni 4000 instead of the 6000 if I could do this all over again. The side cup gets in the way when trying to paint in close quarters. The Aztec will have the same constraint.