Mortgage or Contribute vs Retirement Savings, where should my money go?

There are pros and cons - mathematically the higher expected (but not guaranteed) return of investments would be a reasonable choice, and 3.3% is a pretty good rate (interest is not a problem for you). The main downside if the money is "stuck" there until retirement. I do not know Canada's retirement laws, but I presume that the taxes are deferred, and you cannot remove it before a certain age without penalty. So you're either paying the tax now or tax later on a likely higher amount (if they work like an American 401(k) does).

Another option would be in a non-retirement, low risk investment account that could be used as an emergency fund in case you need access to funds quickly.

Obviously if you have other debts (cars, credit cards, etc.) those would be good to pay off as well.

You should be able to get returns in the market exceeding that 3.3% loan's cost. Invest.

This is the safest leveraged investment opportunity you will ever have.