I've wanted to go to Cambridge/Oxford for a really long time, which is why I've applied, but my main research interests (what I wrote on for my LLB honours, what I plan to research for my PhD/SJD) are in an area of law that is done very well in Canada (better than in Australia, for a variety of reasons) but that doesn't exist in the UK. If I went to Cambridge (or Oxford, if I get in - yet to be revealed) I'd look more broadly at legal history/theory/public law, but in Canada I can zero straight in on my main interest.
Also, I plan to do my PhD/SJD in Canada (or Australia, if I decide I'd rather be less impoverished whilst studying) so I figure I would get a better idea of where in Canada I'd like to do it, and who I'd like to be supervised by, and even whether I'd be better off going back to Australia, if I've done my LLM in Canada. Even if I could get into Oxford/Cambridge for a DPhil/PhD following my LLM there'd be nobody to supervise me (except maybe 1 guy at Cambridge). This is less of a problem for the LLM/BCL because it's wholly taught, but thinking ahead, I think Canada is perhaps the more sensible choice.
Also, as an Aussie, I'm legally and culturally required to adore Canada and all Canadians.
But it is proving very hard to say no to the whole Oxbridge experience thing, even if Toronto is the more sensible choice. I've never been all that sensible