ditto to what scott said. the aztek in capable hands can still turn out good paint jobs. though not orthodox in design as compared to other airbrushes in general, you can still practice trigger control and dialing the right pressure for the right detail level painting.
the major thing people's negative opinion about the aztek is the built-quality as it tends to crap out after a short while. in that case, if you have money to burn, stick with it and get as much practice out of it now and switch to something else later, or you can get rid of it on ebey now while it's in mint condition to fetch a good price and spend it towards a low budget badger or iwata or other brands and get used to the traditional grip on an airbrush, one of the major difference between aztek and others. (it's interesting to see the pricing for azteks in my local hobby shop is way more than a good badger on dixieart.com.) either way, when you are capable of precision control from your trigger finger and have gained enough experience painting different projects, it won't matter as much which airbrush is in your hand.