My biggest gripe with paint guns (and my airbrush for that matter) is ALL. THE. CLEANING.
I purposely use water based paints in my airbrush because I hate cleaning the damn thing.
I've yet have "CPA" paint react on me, they are super EASY to acquire and the colors are easy to match. Oh and never any cleaning, thinning, no eye or breathing protection (with no paint booth) etc.....