Late reply, but might as well --
I rotated at both Phoenix programs and I'm a current intern at one of them, so obviously I'll know more about my own. Both of the Phoenix programs are good, but they are very different, mostly in terms of patient population. Maricopa sees the involuntary patients on court-ordered evaluation; they have over 200 beds combined between both of the psych hospitals. Some patients end up voluntary, but the vast majority are involuntary. The UA/Banner program has a much smaller, voluntary inpatient unit (25ish beds?) and a stronger outpatient focus; it's also a little more academic. The settings in which your off-service rotations take place are also different, with Maricopa's medicine rotations being primarily outpatient. Both sites have great attendings and I got along well with the residents in both programs. I also interviewed at both Tucson programs, which I understand are now combined, so I can't speak to what their program looks like now.
I am not a Phoenix native and I had my reservations about moving here for medical school, but I ended up liking it enough here to stay. I think Arizona gets a much worse reputation than it deserves, for both its weather and its politics.
If you have any specific questions feel free to PM me.