you will proubly need some more mods to turn them good in the deep stuff. i have seen them in action and they dig, if you are in a bottomless hole they will dig down. i never saw them on trails though, but i have seen 27" vamps on the trail and they did good. i really dont know how they compair to the zillas, the zillas proubly pull a little better in the mud and dont dig down as much. these were going to be my next tires after my 27" executioners wore out but i sold my bike in the mean time.
-Aaron
-Aaron