The biggest issue with UPS is when it crosses the border up here. You sometimes have to give them a bit of a push. Most times, they won't notify you for 48 hours if you have duties or taxes due when the product crosses into Canada. Usually I check the tracking and I just call them once it has arrived and ask them what is due and pay it. Gets to me much quicker without too much delay and if it is an expensive item, the less it is sitting around in some warehouse or truck, the better it is.
If they had a better system to pay this online like Fed Ex does, it would be even easier.