law firms prefer good schools...
A tad harsh, I am afraid. Other than U of T, Osgoode and McGill, Canadian law schools are, more than likely, relatively comparable to one another in quality. However, I think that these same schools are more likely to place better in local markets than they would clear across the country. Does that mean that these schools are, by necessary implication, "bad"? No, it does not; it simply means that law firms only recognize a handful of Canadian law schools as being nationally prestigious and placement rates in, for instance, the big shops on Bay Street reflect that fact.
Admittedly, some schools that are coasting on their names, like Dal, still place reasonably well on Bay Street, but that has more to do with the fact that more than a few senior partners went to Dal (or whichever school) back in the day when it was considered every bit the equal of Osgoode, McGill and U of T, than it does with Dal (or whichever school) being considered one of Canada's top schools. (For that matter, some might argue that Osgoode is also coasting undeservedly on its past glory.)
I had a couple of friends at UNB study on exchange at Ontario law schools, one at Western and the other at Osgoode, and they both seemed to think that UNB compared well with these Ontario schools, for instance. However, UNB's name power does, no doubt, pale in comparision with any of Western, Osgoode or U of T when competing for the Holy Grail of many Canadian law school students' lives: articles with a big Bay Street firm. It's depressing how provincial the Canadian mindset can be from time-to-time.
So, a small school that places primarily in its region will have a smaller network upon which to draw when seeking to place its students. If that network is smaller, in absolute terms, and is in an area that is not filthy, stinking rich, then students may stuggle to find decent articling positions. Unless they are near the top of their class, these same students are more than likely going to find it tough to crack Bay Street unless they have some highly prized pre-law school work experience and/or good contacts on Bay Street. (Perhaps a small school like Calgary, which is often not accorded the highest degree of respect and is certainly not considered the equal of McGill, U of T or Osgoode, might fare better than places like UVic, UNB, USask and the University of Manitoba at placing its grads in decent articling jobs if only because it is the only law school in Calgary, Canada's hottest legal market right now. Similarly, the proximity of Western to Toronto, and the fact that it is known to the denizens of Bay Street as a decent law school, likely helps Western quite a bit when placing its grads in T.O.)
So, to that end, I would think that prospective Canadian law students might best be advised to go to the most prestigious law school to which they are admitted. Sadly, many good Canadian law schools are not considered prestigious, and placement rates in the highest paid articling jobs in Canada (which jobs, in turn, dictate how many doors will be open to you later on in life) reflect that fact. Canada is not as egaltarian as the lefties that run this country would have you believe.