In Canada currently. The salaries just suck compared to states. Yes the visa hoops are less but living expenses in cities like Vancouver will suck everything out of your pocket.
Renting an apartment will cost you at least twice as much in San Francisco though - so most people are still financially better off with the smaller salary in Vancouver. There are non-financial reasons to move to the Bay Area (more interesting work being the big one), but don't expect your salary to go farther