I am pretty sure I pay more in Oregon when you include healthcare expenditures. State income tax plus federal plus fica plus monthly premiums for spouse and kiddo ads up to a huge chunk of my take home (over 35% of my gross earnings).
Ya, I was pretty surprised as well. I expected Canadian taxes to be much higher, but they seem to be fairly competitive actually, especially when you factor in other costs as you pointed out. Overall, the biggest detriment appears to be the massive salary cut you would have to take, and less so the taxes.