I lived in Tucson for about 7 years the first time, and 1 year the next time...
Personally I like it better than the Phx area, it's close enough to hit the clubs if you choose or concerts, airport, etc...but Tucson has much better air quality and less crowding, it's also close to Mt Lemon which has a 9k peek where you can go skiiing in the winter most times, and it's only a 45min drive from the valley...and often about 10-20 degrees cooler than the valley at any time...
500k in Tucson and you'd be in a mansion, in the Phx/Scottsdale area, you'd still be in a nice house, but not quit as monster-pimpin as you could get in Tucson...
West side of Tucson is more of the hippie/liberal/college side, north side (district 16) is at the foothills of the Catalinas (mountains) and is probably the nicer side of town, the East side is more of the conservative, but 'ranchy' vibe....and the south side...just say NO...
If I 'had' to make a choice to live in the Phx area, I'd check into the Scottsdale area first, then Tempe and/or Chandler...
this cam usually has a good shot of the Catalinas from the center of town:
http://www.cs.arizona.edu/camera/
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beep me on ICQ if you have any more questions about the Tucson area...
I'm sure you can get some more recent info on Tucson from a few of the topbucks crew...