I've lived in Tucson for the last 3 years and I have to say that Arbre's version of the city does NOT match up to my experiences. It's dusty, yeah, but not grimy. I actually see a lot LESS litter here than many other places I've lived. The mountains are GORGEOUS, the Sonoran desert is as well, and so long as you stay out of S. Tucson crime is really not bad. It's a lot more liberal than most of AZ, has a great art scene, it's surrounded by state and national parks, the desert is wild and beautiful, and I have made some wonderful friends here. Yeah, it's brutally hot in the summer, but it's the desert. It has nothing to do with the city, and you can always go up Mt Lemmon and escape the heat. I think that high 80s for January is a slight exaggeration - it's been low 60s to mid 70s here since December. Not even close to uncomfortably hot. I haven't had to run AC or
heat in two months - it's just right outside. I think Tucson is worth a visit at least to see if you like it. If not, try Flagstaff.
Phoenix is personally not my cup of tea (and Tempe just from proximity to PHX) because it's so huge and the sprawl is pretty bad. Plus it's the kidnap capital of the US! But my tattoo shop is there and I love them, so it's got it's good points too!