Is it maybe too common of a wood? I never see anyone use walnut, and i have seen walnut that either rivals or surpasses the best koa i have ever seen. Also, walnut is a naturally stable wood, and with stabilization, it is IMO one of the best woods out there. I suppose i got curious about this when i started making my stropping boards. I am using walnut, and am amazed at the curl and tones in the woods.
This is a 4 foot board i am using for my strop(stolen form JohnnyChance's thread) and this i would consider a decent board.
Maybe i am just too curious...