I was serious about the third tier toilet comment. I am very anti-mcgill and anti-osgoode. As per opening 'international doors', I would say it would depend on what area of law. If it were in corporate, it would be behind UofT and Osgoode for sure.You will need to speak french for one first year course...that's it. And you can probably get by with very basic knowledge of the language. Plus, Montreal is basically anglo. so you won't need french for daily life. I lived in montreal, and hung around the mcgill, and I don't speak fluent french; didn't seem to hurt me.
the international law program at UofT would put Mcgill's to shame. For corporate and international, i think UofT is far better than Mcgill, and I'm not really a UofT advocate either. For anything else, they are probably closer in comparison, but i would still say UofT is in general, a much better school (if not based purely on admission standards ie. quality of entering class)