USC hands down all the way. Despite the fact that USC's dental program is expensive, probably the most expensive in the nation, and has a problem-based learning curriculum, a lot of USC dental school graduates come out as great clinicians. The downside to USC is that sometimes the professors are jerks, can play favoritism (or your TA who grades your PBL work) and like I've said, the price is too high.
azdoh, on the other hand, is such a disorganized school. They're still waiting for CODA to get back to them, and the administration there is praying their a$$es off that CODA will give them accreditation. They only show the superficial part of their dental school which are the new dental equipments and the new building. Don't let that fool you into going to arizona's dental program. But it's your choice. In addition, arizona's curriculum is always changing. You study a course for two weeks, then bam, another curriculm the week after. You better pray to God that your professor comes back to asdoh to teach if you need a letter of recommendation from him or her in the future. To the administration at azdoh, it sounds "cool" to fly in professors from other dental schools to teach the students at asdoh. But to me and some other applicants at my interview, that teaching method was a huge turn-off. I expect gavin and asdoh companies to come here to criticize what I've written about their "brand new" dental school. But heck, that's my opinion.
Anyhow, good luck with your choice. Like I've said, USC in my opinion is a better dental program than azdoh.
First off, it's ASDOH. Secondly, they don't 'fly' in professors to teach for x amount of time. If you had been listening during orientation, they fly in guest speakers from other schools, and professors there are on 1 year contracts. Thus, if students like the professor, he will likely stay there (many give up their tenure at other schools to teach in Arizona). This is, in most people's opinion, the best way to get quality, caring professors.
Also, I'd like to know which schools give you an "in depth" look at their school in the short time you're there during interview day? Did you stay for a lecture at other schools? Did you talk to the entire faculty at other schools? Did you have a 1 on 1 with the dean at other schools? I doubt it, and would place my bet on most schools giving you the "usual" tour and basic curriculum information. All other information can be found out by you, via conversations with other students or faculty.
As far as the curriculum, again, if you had listened during orientation, you would have known that you are tested weekly (every monday), and that you stay on a topic not for 2 weeks, but for several weeks (please correct me if I'm wrong on this current ASDOH students; this is what I learned from talking to some of you). If this style doesn't suit you, and you would rather take many different, unrelated classes at the same time, then that is your preference. I personally would rather take classes that are related together (I used to hate finishing studying for Ochem and having to open up a physics book).
Again, to the OP, it's a matter of preference. PBL, california weather and relaxed system, higher tuition and higher housing rates for USC versus integrated curriculum, boards after the 1st year, HOT weather, all books on laptop, lower tuition, and night life not so great at Arizona. Both schools seem to have great clinics and high student morale. I have a few friends at USC and they love it there. I've spoken to AZ students and they love it there. I don't think you can go wrong on your choice. Good luck!