OP may have decided already, but in case you haven't, I agree with most of the above. Duluth and TC campus is combined in years 3&4, so the students are indistinguishable. You graduate from the UMN medical school, you don't graduate from Duluth or TC. The reputation is the same.
Many students (~60%) do primary care out of Duluth, however, there are still people who do Derm, Ortho, Radiology, Anesthesia, etc, so it really doesn't limit you, just the students they select are often primary care from the get-go, which makes sense, because it fits their mission.
I'm glad I chose Duluth, because it's a smaller campus and I had been living in the Cities for a while - so it was nice to get out for a few years. Duluth is a really cool city for people who like the outdoors - so many things to do! You can PM me if you have further questions.