I've got 3 or 4 burnt chestnut handles installed. I like one a lot, but generally they're my least favourite. True, the rougher grain is good for gripping, but also being rougher and burnt they're a little more rustic, and so might suit that sort of knife. I don't think they usually suit Kato (and they're not traditional where Kato's from anyway, another slight reason for me), and they definitely wouldn't suit non-KU Shigefusa. To me they're a better fit for Heiji for example, and maybe for various KU knives too, or ones with hammered finishes.
I like them a lot, good grip and aesthetic on the right knife. I have the Kochi 240 suji and 180 nakiri and they fit the style very well. Don't think they would look good at all on my Kagekiyo 240 gyuto though.