I did end up going with a variable rate, prime-0.8 from Scotiabank. I got it directly from a Scotia mobile mortgage specialist who I've used before, maybe that accounts for the 0.05 difference.
I compare fixed vs variable every time I get a new mortgage and I like to run my numbers using the fixed rate, that way I'm sure my property works even at a higher rate than I might end up paying.
Also, 4.75 is nowhere near as high as the prime rate could go. It's been as high as 4.75 as recently as October 2008, then it moved 2.5% in 7 months to its low. Rates often move up or down quickly, not in the lockstep patterns people use for projections. As an example, prime went up 1.75% in 9 months at the end of '05/beginning of '06.
Variable is usually cheaper, but not always, so it behooves the sophisticated investor to carefully consider the available financing options, and make a decision based on available information and their situation.
Regards,
Michael