SinglespeedStu has used the 29er version and I seemed to remenber him saying that they were super grippy but a bit draggy for his usage.
I tried a 29er version on the front of a freak bike that I rode for a while. Seemed good to me, grippy enough, not a mud tyre (but who wants to ride in mud?), nice big volume. I had a 26″ one on the back and didn’t find it too draggy, but in Calderdale a bit of drag is no big deal, with the short climbs and steep descents. Must dig out my 26er and give it more of a go.
Throw caution to the wind and try some. At least you’ll have a different tyre to talk about.