Wow you're making me re-consider my choice to attend Penn haha. The people who went to Tufts were friendlier.
I'm not looking to start some argument about Tufts vs. Penn. I went and saw Penn when I lived in Philly. Great campus. Great school. I didn't apply there because after living there for two years, I'd had my fill of Philadelphia. I'm not sure if you have lived there before, but Philly is not for everyone. Some people really like it, though.
After I hit a certain level of schools that I felt all had great facilities, technology, location, name/reputation (even though I'm not sure how much this really matters), curriculum, preparation clinically, board success, and faculty, then the happiness of the student body did have an impact on my choice. For example, the students I met on my USC interview seemed to hate being there. I had other complaints about USC and didn't have them anywhere near the top of my list, but that also bothered me. I don't want to be in my classes with a bunch of students that felt they settled for their school, wish they were somewhere else, and dislike the program/curriculum. From the students I spoke with at Tufts, they felt they learn a lot from the curriculum, love the school, and seemed to have a great relationship with the faculty. I'm not saying everyone at Tufts definitely feels like that, but it seemed to be what I mainly encountered while there.
Also, as I met faculty that were pretentious and rude at other interviews, I thought it was refreshing that they didn't feel the need to be that way at Tufts. I'm going to have to be around these people for the next four years, and I'm going to be associated with them after I graduate. I thought these things helped separate Tufts from the other schools that also had great resources, facilities, etc.. Obviously, I really liked the school. You don't have to feel the same, but that's just how I felt after considering all the places I interviewed. As Penn is your choice, I hope Penn is all great things for you. Penn is an amazing school, but so is Tufts. Personal preference.
I realized the probable sarcasm of your post, but I decided to treat you like a mature adult with a real response.