I have two Extreme's, found the little screw on the bottom for regulation to be relatively ill fitting and not useful on the first one, had Ken at Badger make one for me without tapping the barrel for threads. I regulate prior to the airbrush, simple really. Nice airbrushes though.
Depending on what you will be painting, I'd recommend you first check out "Don's Airbrush" website. That might give you some insight as to the type and brand that will work well for you.
Of all my Badger airbrushes, the one I use nearly all of the time is the 100G, followed by the 100LG. Those cover my bases best overall. Very rugged, low cost, give them good care and you'll have them for a lifetime. One of mine is well over 40 years, still works perfectly with minimal parts replacements.
Patrick