I was accepted to both. I chose MWU-AZ for a few reasons. First of all, UoP was my favorite interview, and was my #1 before I even interviewed there. Oddly enough, MWU-AZ didn't impress me much during the interview. I felt like they were trying to sell me a bunch of stuff I didn't care about. But the more research I did, the higher MWU-AZ climbed, until it gained parity with UoP. Some of my circumstances are unique to me of course, but here are some of the things I considered:
1. The 3-year accelerated curriculum worried me a bit. I am in no rush to finish despite starting school at 30, and I saw no significant financial benefit to attending a 3-year program over the 4-year program once factoring in the debt load and cost of living situation.
2. Both programs are similar, but you get the extra year at MWU-AZ. I had no idea what my hand skills were like (I still largely don't) and so I would rather err on the side of caution and assume that I need more practice and time to really get to the level of competency I want to achieve out of school.
3. San Francisco is outrageously expensive. Even in super nice Scottsdale we are paying a fraction of what we would have for a smaller place in San Fran.
4. My fiancee had a job offer in Phoenix, though we would have figured out a way to go to San Francisco if I had really wanted to. UCSF was hiring in her field, so it was possible.
5. Students I spoke with at other programs during my interviews were super impressed with MWU-AZ students they had done residency interviews or externships with.
Both are great schools, probably the top clinical programs in the nation. I don't think you can go wrong with either, I recommend that you list the pros and cons of each and go from there like I did.
A few things I like about both schools.
The culture is phenomenal
Top clinical training in the nation
Boards after the 1st year and then you focus on clinical dentistry from there on
Great faculty and staff
Both schools are progressive and changing, they are not mired in tired old traditions
UoP has some distinct advantages though:
San Francisco is a great city to be young (though Phoenix has its charms too)
UoP has one of the most powerful alumni associations in the nation
They have an incredible history and have produced some of the nation's great dentists
Everyone in the field knows UoP's reputation
3 years and then you are DONE!
The downsides to both which I'm sure you know:
Expensive
Low specialization rate
Expensive
Intense 1st year
Expensive