I have no particular opinion other than I generally prefer common law entities over statutory ones. In addition, please be aware that the kind of common law trusts that Randall sets up can operate as foundations. The only possible disadvantage I can think of is that if you are accepting donations and you want the donors to be able to write off their donations on their tax returns as tax deductible, then your foundation may have to be a statutory entity. I'm assuming that's what you are referring to in Canada, as a Private Interest Foundation. In the US, a 501(3)(c) can operate as a foundation and be tax exempt, but it is a statutory entity and thus is subject to a long list of regulations. It does, however, offer the benefit that donors to it can have their donations be tax deductible.
If your foundation is philanthropic and will be giving donations rather than receiving them, then the common law trust that Randall provides you could be set up that way and would be far superior, in my opinion, because it would have no tax agency or government filing requirements and would therefore be subject only to the common laws -- i.e. don't lie, don't steal, don't violate the basic rights of others, etc. It would be free of the millions of ever-changing statutes legislated by politicians and lawyers every year.
Or, if your foundation will be receiving donations, but you don't care whether the donations will be tax deductible for the donors, then too, the common law trust would be superior.