For me, I gave up cheaper options and I would do it again in a heartbeat.
Columbia and Penn are pretty opposite in certain respects, so it depends on what suits your learning style better:
1) Medically Focused Vs. Medically Integrated :
I personally wanted a strong dental focus. Penn has their own dental faculty dedicated to the school. Every subject we learn has a dental focus - we're taught how what we're learning can be used clinically in the dental chair; I never feel as though I am competing with medical students for teaching. Despite boards being pass-fail now, schools still receive statistics on how they perform relative to other programs; Penn scored in the top 1% for two very medically based courses, Pharmacology & Pathology, so I think we do a pretty stellar job with the medical curricula, too. I also think if you look at the clinical portions of national boards/licensing: NDBE part II and the NERB, Penn is doing a phenomenal job of clinical training vs. other schools.
2) H/P/F vs. Grades:
I personally thought I would have wanted a pass/fail program, until we started our one pass/fail course. I didn't take it very seriously because I had a graded course to study for. There was no point me in putting all my effort into the course that didn't really hurt me. I think H/P/F takes discipline and self-control - if you are absolutely going to go balls to the wall for every exam, pull all-nighters, and do all you can to learn the info, then H/P/F can be great. Any program can be pass fail, if you want it to be. It just depends on how much you want to know for your patients in clinic.
3) Clinical Training:
I don't know what Columbia's requirements are, but Penn's graduation requirements are very rigorous. We used to have 15 intra-oral canals required for graduation (most schools will require 2 canals, tabletop, some on plastic teeth) - we recently moved it down to 7 (i think?) due to medicare changes, which is still far beyond most schools. I think there is only one school on the West coast who has more arch requirements for dentures (complete/RPD/FPD). In order to graduate from Penn, you need to clinically competent. So even if you don't choose to specialize, I think you're going to be more prepared for doing a competitive GPR or private-practice.
I think those are the biggest differences between Penn and Columbia. I'm sure there are little things that each school offers that makes it special. I really enjoy the following at Penn:
1 - DAU program. You're in clinic for all four years. In your pre-clinical years, you spend about 8 hours in clinic every week - assisting, learning where everything is, setting up Xrays, doing impressions, etc. In second year as an EFDA, you are restoring teeth, placing rubber dams, packing cord, etc. It definitely allows for a smooth transition into clinic, so we're not so lost in 3rd year.
2- Selectives - we get to take a lot of self-interest courses, such as esthetic & cosmetic dentistry, 'paying for the bmw', comparative oral surgery in animals, etc.
3 - Honors programs - we offer 4 honors programs (Clinical Dentistry, Community Service, Research, and Medically Compromised Clinic) which allow you to take on project that give you more in-depth exposure to various areas.
4 - It's on the main campus. Being integrated with all the undergraduate and graduate schools gives a real campus environment. You can take classes with other schools (if you have spare time or an interest in that), go to all these inter-graduate school events and mixers every week/month, do a dual degree (DMD/law, DMD/MBA, DMD/Bioengineering, DMD/Higher Education, DMD/Bioethics) or research with another school, like the vet school.
5- Exam schedule. I think having 1 exam/week is probably the best set up for me (occasionally a 2 exam, or 1 exam + quiz). I never get swamped with too much information that I can't handle. Never have to deal with 7-10 exams at once. Whatever I put into my studying, I get out with my grades.