The Smith Manoeuvre is an interesting idea, not for the the feint of heart, which in an obtuse way allows you to deduct your mortgage interest (kind of).
The question really is not only, RRSP or Mortgage. The real question is savings or pay off debt. Can you run a marathon with 100 extra pounds on your back?
The Smith Manoeuvre is a way to make your Canadian Mortgage tax deductible (the interest on the loan). Is this a good idea? I think it is incredibly risky, and asking for trouble with your future. Others swear by it. Are your mortgage interest payments that high?