I've only seen it used on a couple of guitars and it seemed to sound good and was spectacular to look at (a beautiful warm red hue). The guitars I saw made with it were by Bill Moll and Kirk Sands- both visual knock outs.

Any thoughts...sound quality? availability? cost?

Cocobolo is very much like its' close cousin Brazillian rosewood in most aspects. It is however highly toxic. An ex-partner of mine was so sensitive to the stuff that if he picked up a stick of it by mistake in the shop, you could actually watch his forearm swell up. My apprenctice was also very sensitive to it, and collapsed at the bench one day while we were doing a run of fingerboards and bridges. A Canadian luthier called Don McPhee sawed a pile of it into sets about 18 years ago, and within a few months his lung function was impaired to the point where he could no longer work. After years of deterioration of his lungs and overall health, he underwent a heart/double lung transplant about 2 years ago. He didn't make it. Needless to say, I don't use much cocobolo these days.