I have had Maxxis All Tracks 22" on my 400EX. They were much better in mud and jigrock hill climbing than the stock tires. The extra 2" helped in mud, plus the All Tracks have fairly huge knobbies. They wear excellent. They don't slide too good though. I am running Shredders currently, but they don't compare at all to the All Tracks for snow and mud.

 

Try a set of Trail Claw 2's.22/11/9.. They are great in the woods and for hillclimbing.They work well in rocky areas also.They even slide good..I have seen them in action on my friends 400ex and on Banchees.