I personally have flown to Phoenix and spent a week on campus speaking with current students, sitting in on lectures, touring the facilities, and speaking face-to-face with the Dean of Admissions. My honest, unbiased opinion is that Thunderbird is a fantastic, invigorating enviornment.
The campus is small and tightly knit. No punk undergrads or other carefree kids "skateboarding" down the mall (no offense to any boarders out there.) Thunderbird is a Southwest premium school geared strictly for the mature, open-minded, internationally focused MBA aspirant.
I saw people from dozens of different countries, all mature adults (25-40yrs old) enjoying (and of course learning) MBA life.
Besides the dry desert climate, the one main drawback is the $$$$ tuition fee. Don`t even think about applying for a merit based scholarship unless you have a 650+ GMAT and excellent credentials. Other funding is available, and usually given, after you matriculate and maintain a 3.5 GPA.
Incidentally, one of my colleagues will begin his studies at T-bird this month. He just relocated from Japan to Arizona last Friday. So if anybody has any "campus culture" related questions, I can easily shoot him an e-mail.
One final note, even though Thunderbird is ranked #66 or so, it does have a strong connection with Citicorp and GM, not to mention a host of other big corporations that actively recruit on campus every October/November.
Thunderbird is not my "dream school," but most likely my target school for fall 07.'