I find this whole debate a bit confusing. It's not like it's in a program's best interest to over-invite for interviews, since it costs a program time and money for each person it interviews. If Vermont felt like they could interview fewer than 500 people in order to adequately create their ideal class, I'm sure they would jump at the chance to cut back and eliminate a whole month from its interview schedule, saving everyone - program and applicants - a lot of hassle...so by spending so much time interviewing so many people, it shows that UVM obviously feels that each and every one of the 500 interviews are a necessary part of the process to fill the incoming class.
If Vermont cut interviews by 20% down to 400 people, I bet a fair percentage of the current students would not have made the cut, because fewer interview invites tends to mean more emphasis on statistics like GPA/MCAT, because there has to be some sort of cut-offs to whittle down the number of applicants. Does the fact that Vermont puts less emphasis on scores and more emphasis on life experiences and the fit of one's personality make it an "average school for average applicants"? Maybe, maybe not; that's up for you to decide. I personally think that's what makes the school special - there are people at UVM who were studs in undergrads with their 3.9+ GPA/38+ MCAT and there are plenty of non-traditionals with amazing life stories that don't come across as well on paper as they do in real life, so I'm glad they were given the opportunity to shine at an interview.
I'm not going to get into the whole research vs. primary care rankings debate. If you want one of the top-notch primary care educations, you'd be hard-pressed to do much better than UVM. I'm going into a primary care speciality (pediatrics), and I've been told on the interview trail that I'm going to have my pick of residency choices. I don't say that to brag at all, but to show how well UVM has prepared me for my career choice - having "UVM" on my application garners respect because I've gotten to work with some of the bigger names in the field, including the editor of Pediatrics who wrote me a letter of recommendation (he even goes so far as to give all UVM pediatric applicants his home phone number if we have any questions/concerns during the application season). This is less common in some of the bigger programs with lots of residents, where the students rarely interact directly with big-name attendings, never mind getting to know them on a personal level.
If you're not a primary-care person, Vermont is still a very good choice. I'm really excited to get to see my class's match list this year - we have over 25-30 students applying in surgical and ROAD specialties who have been interviewing at top programs all over the country. Several of my classes scored in the 250-260+ range on step 1. Students have presented research at top conferences. Sure, it might take a bit more effort to land a top ROAD residency coming from UVM than from an institution with a bigger name attached to it, but that hasn't stopped motivated students from UVM from ending up at well-known programs all around the country.
I hope this post doesn't sound defensive, because I don't intend that at all. If UVM is the right school for you, that's wonderful, and I hope you get in. And if it's not, that's great too, and I wish you the best of luck in your careers. The right school is out there for everyone, and for me it was UVM, which I chose to attend over my cheaper state school, and I don't regret that at all. And if UVM is the right school for you and you end up on the waitlist like so many do (I was OOS waitlisted for 3 weeks before getting accepted), don't give up - call/email with updates, LOIs, etc. If you have a connection to Vermont or a specific reason why you think it's the perfect fit for you, don't hesitate to let them know, because UVM wants students with the right personality fit who are committed to serving the people of Vermont.
I apologize for the long post; you can see that I'm passionate about my school! I know you guys get to meet our wonderful 1st and 2nd years on interview day, but due to logistics most of us upperclassmen aren't available, so please don't hesitate to ask me any questions (either in this thread or via PM) if you'd like to hear more from someone who's gone through almost the entire program at this point. Because while the curriculum of the first 2 years was great, it was really during my 3rd & 4th years when I began to fully understand the value of a UVM education. I couldn't be happier with my choice right now (although years from now my bank account may disagree, but oh well).
Best of luck to all of you waiting for good news this cycle; happy holidays!