The numbers by the classes are credit hours, and that is indicative of how many hours a week the class meets. I'm not sure how Canada's credits transfer into US credits, someone else will have to clarify that one. If you call St. Matthew's, Ross, or St. George's, they can probably explain it to you.
You hear little about St. Matthews because it is so new. But that doesn't mean that it is any worse/better than other schools. To be honest, if I didn't get into St. George's right away, I was going to apply to St. Matthews. I've heard wonderful things about the school, and I'm sure you get the same quality of education there as anywhere else. I know people always say "Oh, I heard of a vet that went there and he was amazing/awful.". Really, it's the person that makes the veterinarian and not so much the school. You will get the same information there as you will at other schools, it's what you do with the information that matters.