I think this time it's ok, the US/Canada models seem to be the same and support the same bands as long as you get a A1533. The Sprint one is even a bit better with an extra band (that doesn't matter in Canada), but I doubt you could buy one unlocked from Sprint.
http://www.apple.com/iphone/LTE/
Though I guess it still only supports one of the two LTE bands that Rogers and Bell (and I assume Telus by extension) support.
http://www.extremetech.com/computing...orks-worldwide