Well, I jumped on the Ci0 bandwagon recently, and now that I've used it a bit, I thought I'd offer a review.
I got mine from Craig unhandled, since I have Monster tool handles that I'm real fond of. (BTW, the Monster handles are still on sale. See the Commercial Post Zone for more info.) As expected, the fabrication and finish of the tool was flawless. It's not just your average piece of square steel stock with a notch cut in the end of it. And the round carbide insert is sharp. Very sharp.
So far, I've used the Ci0 on the inside of a couple bowls after coring. One was a 22" elm piece that's drying now. I just used the Ci0 to clean up the inside after coring, but it only took a couple of three passes to have things cleaned up and ready for the DNA bath. The other piece I used it on was this box elder burl bowl, which was turned to finished thickness from the get-go. On the burl bowl, I still had a an inch or two of material to remove after I cored out the middle, but the Ci0 was the only tool I used on the inside of the bowl (other than the McNaughton). I didn't really push it hard to see how fast I could hog out the wood, but it was apparent that I could have done so if I'd wanted to. There was no tearout (important on wild figure like the burl), and no fear of catches or other nasty surprises. Sanding started at 120 grit. The tool was very easy to control, and the fear factor was non-existent. This was especially apparent and appreciated when I was cutting right at the rim of the bowl.
There were several words that came to mind while I was using it:
Craig, you've got another winner here. Thanks!