I'm back in Montreal for the first time since 1992 (came back to Montreal last summer), and oh, how much of a learning curve it is to be launched into the spring apartment-hunt! God help anyone who hasn't lived here prior to coming to Montreal, and God help you if you don't know French!
Having lived in Montreal before is a huge help. For example, I knew that most leases are swapped on July 1st... you don't know this little tidbit, and you're already behind in the shuffle. Also, as my lease is all in French, the French I learned in Montreal last time meant I could read it(!), and this means that I discovered that landlords can demand three months' notice... this means that July 1st is moving day but March 31st is apartments-starting-to-become-available-day! Tricky!!!
So, Montreal is an art unto itself. The Plateau is the place to be, but in the paper the "Plateau" can be anything from the eastern edge of the McGill ghetto to the end of Mont-Royal Est to Mile End!
Also, this does not mean that other parts of Montreal are undesirable: Outremont, NDG, Verdun, anywhere in Montreal West can be perfectly good. So it's not all about the Plateau Mont-Royal!