You have a rather wide range of colleges and universities that you are considering transferring to. They differ in terms of size, academic rigor, location, and other factors. I am a bit concerned that you might not know exactly what you are looking for, which in turn makes it hard to find a good fit.
If we knew your major and what school you are transferring out of that might help us to give better advice.
It is hard to imagine a university with 6,000 students that does not have at least some range of different types of students with different interests and different backgrounds.
McGill is very large, somewhat bureaucratic, and is academically very challenging. It will be quite transfer friendly. If you come in as a U1 student then there will be many other students coming in at the same time – including the various students from Quebec who are coming in after two years of CEGEP. “Diversity” in Montreal will include native English speaking Canadians, native French speaking and fully bilingual Canadians, and many students from outside of Canada. This is a difference in culture and background, which is different from the way that the US talks about “diversity”. McGill is right in the middle of a very interesting, culturally rich, and bilingual city with French being the majority language. You will hear lots of French and lots of English and some other languages spoken in the area, and you will overhear some conversations that switch back and forth between languages right in the middle of a sentence. The small mountain in the middle of Montreal is not going to support much in the way of downhill skiing, but I am told that many buses full of downhill skiers head off to nearby ski slopes on Saturdays in the winter.
What is your home state and what is your budget?
A small school such as Ithaca College (6,000 students) or St Michaels (2,000 students) will have fewer majors compared to somewhere like McGill (40,000 students) or Colorado State (34,000 students). It will be a very different experience.
Colorado State is a school that I have thought of as an example of how either rankings do not matter at all, or depend a great deal on what your major is, or both. The last time that I looked US News had it ranked 153rd overall, but 3rd in the US (and 4th in the world) for Veterinary Medicine. It certainly deserves its high ranking for Veterinary Medicine – the program is superb. I have no idea whether it deserves its lower ranking overall (other than there being 152 other universities that are also very good).
I agree that the University of Vermont is an interesting university to consider. It is rather expensive unless you are either in-state or qualify for a presidential merit scholarship. I also agree that U.Mass Amherst is a school that you should consider.
If budget matters then something that is in-state for you is worth considering. Students often tend to under-appreciate their in-state public universities.