Well, I just took delivery of a guitar via UPS ground, with no (apparent) problems. It was in a plastic hardsell SKB case, which was in a cardboard box filled with styrofoam peanuts (mmm... peanuts...)
I am a wee bit surprised, however, that despite the fact that it was insured for a significant amount of money, they left it outside my front door, in full view of the street, and didn't require a signature. If I were a less honest person, I would have hidden it beneath the floorboards and denied receipt...
UPS Tracking site still shows "in transit". I wonder where it's going next.