I've had 224 deliveries in the last 12 years, and they all went well. The only problems I've had are with DHL, and I no longer ask to use them, so that's not the fault of usabox. You can check the box for FedEx, and they've been great.
I think the comments below are unfair to this company. Nothng was ever lost, and I was never overcharged. On the other hand, DHL employees here in Colombia do not understand their own policies, and sometimes sit on a package without knowing it.