Jessica, I haven't used one of Bu-Jin's, but there was a prototype laying around the shop for most of the 90's, and it was pretty sweet.
Dymondwood is a bit brittle, and I've seen them chip under certain circumstances, so it's important that the tip not be too sharp. I had a jo made from the stuff for awhile, and it was nice. Same deal, you really have to put a decent bevel on the ends to prevent chipping. But with that, there's no problem. Just don't stand around in the dojo parking lot talking and tapping it on the pavement.
The stuff is dense, so expect some heft.
Of the pile of weapons I've collected, I always go back to a giant curved Iwama made of white pine and a small Bu-Jin bokken of hickory. For jo, I think Bu-Jin's hickory are great. The lamination gives you a better shot at keeping it straight over a few years.