I agree with every one of Chris's points. I don't want to comment on the studies he mentioned though, since I haven't seen them for myself.
The thing I want to underline though, is that for me, I don't DISLIKE the vest. I simply LIKE good chest PT more. With that in mind, however, the vest has been a lifesaver after I moved away from home. If it's done properly it can be an extremely useful clearance tool. I would only recommend it for after your daughters get older for the reasons Chris mentioned though.
Kinda off topic but I find it very weird that Canada will pay for everything else but not the vest. Ahh, trade offs, I guess. <img src="i/expressions/face-icon-small-smile.gif" border="0"> I think all the negative propaganda your clinic is throwing at you is probably in relation to it not being covered. Just ask SaltyandSweet about insulin pump coverage. I've never heard bad press about the vest here (or good, either, I guess) and I've certainly never had chest pain in the 10+ years I've been using it. If you're having chest pain, to quote my favorite meme, "You're doing it wrong." <img src="i/expressions/face-icon-small-tongue.gif" border="0">