Clear and balanced sound, lots of volume, not too heavy and easy to move around.
We got these for our practice space and we play metal fairly loud. These have enough output volume to make sure anything you put through the PA can be heard. The sound quality is excellent, very balanced with no noticeable frequency build-ups. We actually first ordered the Mackie SRM 650s, but due to availability issues swapped to these. That was a good choice, because the Mackies seemed to have a much more boomy low/low-mid that wasn't desirable. These Yamahas are excellent.
Plastic housing seems rugged enough for road use, the handles are good and easy to grip. The weight isn't too bad, a little bit lighter than I would have expected.
Can't comment on durability yet, but Yamaha gear has not let me down thus far.