There will probably be lots of opinions on this. In mine, it is not too good to be true, but there are a lot of things to consider. First, if your mortgage does not have a home equity line of credit attached to it, you will need to break your existing mortgage to get this, and there will likely be penalties involved in the thousands of dollars range.
Second, you will be leveraged to the hilt for a while. That means you have to be very comfortable with debt, and you will likely not be able to get any more credit should you need it. That means, unlike most Canadian families, you should have a goodly chunk of cash put away for emergencies, because you will not be able to borrow any if you need it.
Third, moving or changing houses becomes somewhat difficult. If you move, the lenders may call in their debt, and if you are using Smith's Accelerated plan, where you have a lender give you 3:1 for your "Freeboard" home equity, that could be a bit of trouble.
Fourth, you need to have a high enough income to generate the most tax advantage. If you, or your spouse suddenly drops in income, you will not be getting the same tax advantage.
Fifth, you need to be very careful of the investments in which your advisor is putting your funds. They're probably secure, but if they bottom out, that is where the risk in a leveraged strategy comes in. However, if you are using competent people, this should not be an issue.
Beyond these sort of practical issues, I believe the theory to be sound and a worthwhile endeavor if it meets the practical conditions I outlined above.