They're a good tyre, not great imo.
They're a few years behind the tech of Dunlop and Yoki.
Having said that, I have only used them in smaller sizes of 235 and 265.
We were fortunate to back to back the V70A's against the Dunlop O3G's at Mt Buller once, the Dunlops were nearly exactly a second a klm faster.
In the rain though, I think the Kuhmo is wonderful, I just think they struggle a little on heavy cars.
As I allude to though, they could have completely different behaviour in the enormous sizes.