95 % of my customers are U.S. I have found almost all my customers (U.S. and Canadian) to be great. The only difference I notice is that Canadians tend to be very much smarter (cheaper?) buyers. For my auctions, if it is a Canadian winner, I can pretty much guarantee that the auction was really low. Not always, but most often that is the case. And I have never known a Canadian to use BIN. Even with a $20 or $30 difference between auction listing price and BIN, U.S. eBayers often use BIN.
On another note, I guess I am pretty much alone here in thinking Canada post is Great. I ship glass, and out of well over a thousand shipments, only two have had any damage. Granted, I do pack well... but even so. I also find the postage (especially to the U.S.) reasonable, and sometimes cheap (oddly, the bigger and heavier the box, the better the deal).