Sorry cader28, didn't mean to give you a paper cut there over the aztek.
I started out using an Iwata micron and loved it. But like any precision instrument it has to be treated with kid gloves. And the maintenance on a piece of equipment like that equals the price.
I started using Aztek years ago and have been using a 430 now for a while. Its a good little brush. The beauty of it is in its simplicity. Once you get over the psycological hurdle of the thing being so light because it is made of plastic (or a composite) it just takes some rethinking as well as new work habits to get used to. (I've been looking at the new metal bodied version just because I would like the extra weight in the brush) I've used it for illustration, doing detail work on props, models and other applications with little or no trouble. Despite what the factory says or reccomends, you can take apart the head for a thorough cleaning. But remember those parts are fragile and are not made for this repeated type of unauthorized maintenance. As has been said before this is not for the timid. But I look at it this way. I was going to toss the head anyway so no matter what I do to it it can only be an improvement. Worse case you toss the head and buy a new one for $8 or $9. If you drop it, because it is light it doesn't do alot if any, damage to the nose, as opposed to lets say an Iwata that if you dent the nozzle thats $20, a new needle as much as $10, close to to half the price for an upscale aztek kit, so the $9 for the whole assembly isn't bad. With proper work habits and practices the heads shouldn't give anyone trouble. The body has a lifetime warranty. Until I became familiar with mine it was a fight with the brush to see who would shoot first. Spatters, back pressure into the cup, clogs, I constantly fiddled with the thing. But I worked through it. Once I realized what each problem was and what was causing it I was able to fix it.
Like anything, with familiarity and practice comes success and satisfactory results. The more you use it the more comfortable you become with it and see its shortcommings and assets. The most important thing is not to expect it to do something it is incapable of doing. Or to expect more from it than is possible. The first model you built may not be the best but the recent models you have built have no doubt stepped a quantum leap from that first one. Because you know what you are capable of and work within your expectations and abilities.
Each person has his or her dislikes and likes. I know guys that say the same thing about Iwata, Paasche, Badger, Vega (Thayer-Chandler) etc. Chevy vs. Ford. Panzer vs. Pershing, Corsair vs. Zeroe and so on. Go with what feels comfortable for you and what you are happy with. If the Aztek is your bane then I suggest you find a different one. Because no matter what you try or practice you will always look at it with a jaded eye. You will expect to fail or have a problem and therefore get frustrated with it and dislike it even more. A sort of success and satisfaction at failure. "See, I told you this thing sucked!"
I'm not trying to lecture you on the philosophy of airbrushing, nor am I trying to sell you back onto Aztek. It does have its shortcommings. Its too light for many. There is a limit to its capabilities. I probobly wouldn't run automotive laquer through it, that will kill almost any airbrush. For those who like to tune up their airbrushes, you can't. And I do honestly belive that Aztek is like a Fiat. You either get a good one or you get the spawn of the antichrist. There is no in between. I am more trying to alleviate your frustration through information and seeing it in a different light. Playing devil's advocate so to speak. (Maybe in this case literaly)
I wish you luck in your pursuit of the perfect airbrush. Endeavor to percivere. Or might I suggest 1-800-BearAir or 1-888-Bearcare (their after sales servcice line)
If you like, e-mail me and maybe I can help you with some fo the problems you've been having with it.
Mike