An HP mechanic would know very well that a -200 is a pain to maintain, but only a bean-counter would know exactly how much money they make. I'm not a bean-counter, but I guarantee you the -200s are money-makers, or they would not be in the fleet. As far as performance, they pack those things tight--their main limitation is on longer routes with weather which limits available alternates. Phoenix has plenty o' runway to get 'em off with a handsome payload to places like ELP and ONT.
A -200 may require more regular MX, but I seriously doubt that a -200 has poorer dispatch reliability than an A320. It may be old, but well-maintained, it is reliable. Now as a passenger, I'd prefer an A320 with spacious seats, entertainment, and bright interior.