Just picked this Ebony Bokken up yesterday and I can tell you how solid it feels. It's a very dense wood, yet it feels just a little heavier than what I use in the dojo.
Funny story goes with this purchase. I saw this online and saw the store was not too far away from my work, so after I got off, I took a hop over. When I got there I went in and I thought I was mistaken because it was a motorcycle parts and accessories shop. I checked the address outside.....yep.....this was the place. I approached the counter and the guy asked if I needed help. I said "Uh....gungfu?...." and he says"Oh sure.......what do you need?" I said I wanted to see the bokkens and jos, so he goes in back and comes out with some. They weren't what I was looking at online and asked if he had the dense one. He goes "Oooooooh.......Yeah....We keep those wrapped...Be right back." The moment he unwrapped it and let me hold it, I bought two!.
The wood belongs to the ebony family (genus Diospyros). The wood is very strong and solid and claims to be unbreakable. Can't wait to try this lovely out with my practice partner, who is also the recipient of the other one I bought.