well, i will put myself in the minority and say that i have no complaints w/ my Aztek. have been using it for about a year now, mostly w/ Tamiya Acrylics.
easy set up, easy color change, easy clean up.
is it the best tool for every airbrushing job?
no.
but i do mostly 1/48 and larger aircraft and 1/24 autos.
i do not need to paint very narrow lines for camo (so far anyway),
so i have not run into a situation where the brush was the problem.
(now and then the nitwit who masks my planes before i paint them let's me down) :-)
it is the only brush i have owned or even used, so maybe i just don't know any better.
but i am satisfied.
maybe the day will come when i will need a 'better' one.
but it looks like it will be a while before i grow out of this one.
ed.