Here in Vancouver it's not very easy to find talent these days, but I think that it's easier to retain talent.

Compared to SV your burn rate could be lower because salaries are lower and you can get significant government funding (sometimes you get back most of the salary paid to some employees, see SR&ED and IRAP).

When it comes to the ecosystem, especially mentors and angels / VCs, SV wins big time.

I've never hired anyone, so I can't offer much insight here. It sounds like Canada has less immigration issues than the US, but I imagine most startups aren't going to be paying for employees to relocate internationally so that's probably a moot point.

Yes, Tarsnap is bootstrapped. Yes, I would have considered staying in Vancouver even if I needed to take funding; obviously I can't offer a subjunctive forecast for how that would have gone, but I've had no shortage of angel investors and seed-round VCs emailing to ask if I'm looking for funding.