To add to my previous post as far as I am concerned the Pirelli Scorpion AT was by far the most awsome tire I ever had on the XJ, its ability on wet roads was downright awe inspiring, treated wet roads like they were dry and basically ignored water. As far as snow was concerned they tended to ride on top of anything over 3" deep, off road they were very good on sand, dirt, mud and rocks. They even worked well on wet leaves covering rocks. Downside was milage, they only lasted about 55K and the sidewalls started cracking but that might have been my fault for using tire cleaner and armourall and formula 303.
I did not buy another set because Sears stopped carrying them, originally when I bought them Sears had them for like $59 a tire in P235/75R15, when it came time for another set they did not have them anymore and the local pirelli dealer wanted about $150 a tire so I bought Dunlops Rover AT's, they were OK, not near as good on wet roads but other wise they were OK, lasted about 70k. I now have the BFG AT's and am happy with them, will be replacing them with the same tire only bigger in another couple of months when the OME goes in...