Had an issue where the package they had delivered to me looked like it fell off the truck. The box was nearly destroyed and some of the contents damaged. Despite all the proof with pictures of before and after and it being well packaged and marked fragile UPS absolutely refused to pay out the insurance claim. The seller was good about the whole situation and refunded me some money (I was able to repair/replace the components that were damaged on the circuit boards - at least the boards were not cracked).
I usually never use UPS because of their lame brokerage fees, and after this, I know the seller isn't using them anymore either.
FedEx and USPS seems to be much more responsible with my dealings with them - not once has any of my packages showed up with even the slightest amount of damage and I buy a lot of stuff online (way cheaper than what I can get here in Canada, not counting the stuff I can't buy here).