I've bought plenty of stuff from our friends up north, and have shipped a fair amount of things there. All shipments involved Canada Post and I have no complaints about items coming my way. I have never been charged customs duties for incoming, including a huge, super heavy Toronto-built Stromberg-Carlson 694 table radio.
The other way, it's different, however. I recently sent a mint-condition Triplett 3444 mutual conductance tube tester to a friend in Ontario. I showed a reasonable approximation of the tester's value (they go for $1,000 or better) on the USPS customs declaration and Canada customs nailed my friend $200 in taxes!
