The pBone is a good looking lightweight plastic trombone which is not too bad for its price. It has a decent sound, although perhaps not as loud as a regular brass trombone. It comes with a plastic mouthpiece, which is a funny novelty. The horn and the bag are both very light and it's easy to carry the pBone along wherever you go. The plastic doesn't break easily so it's a good choice for outdoor playing in questionable weather conditions.
The biggest weakness of the pBone is the slide, as one might expect. The slide works quite nicely when it is clean and dry (it still makes some noice mind you), but after playing for ten minutes or so, some humidity and moisture gets between the inner and outer slide and it starts to stick somewhat. It can still be played, but it is annoying when compared with a regular slide. Slide creams and lubricants that I have tried made the slide worse: dry with nothing on works the best. The slide should get better over time as it is used more and the fiberglass should get smoother and smoother. Still, after a few years of occasional playing (more in the beginning), it is as bad as it was when I bought it.
The zipper in the bag broke a few weeks after I bought the pBone. The bag seems quite cheaply made.