Most Michelins are great tires and the Michelin X-ice is a great tire for winter. I actually used them summer and winter on my Tundra.

I am not a fan of MXV 4s. If you have 18" wheels give the Latitude Sport a shot, they are a Porsche fitment but work well on the X5. Currently I run 19" Diamaris on the 4.4 and they work really well.

On the 4.8iS I am running Latitude Tours and they are fine.

I absolutely dislike Bridgestones in any shape or form. Some Continentals are ok but the current Cross Contacts on my Tundra I am not so convinced about. Good luck.

I run 20 inch Bridgestone Dueler H/L Alenza in the spring, summer and Fall.
Very good tires, I am a pretty aggressive driver and like getting into the curves at nice speeds. If the tire could not handle it I would have swapped them out immediately since I went thru a couple of different brands before settling on those.

For the winter I run 17 inch Pirelli Scorpions Ice and Snows. I have found with this setup I get nice grip year around.

Looks like i'm in the market for new tires. I have a 4.4i with the sport package. 19 inch staggered set up. I am currently running the Pirelli Zero Scorpion Asimmetrico but apparently the tires are discontinued. I got about 20,000 miles out of them. I'm looking for All Season tires due to the fact I don't want to swap out tires.

Right now i'm looking at the Michelin Lattitude tour HP but they are pretty high in price. My other options that I would like are the Continental ContiCrossContact UHP and Kumho Solus KL21. The Kumho's are the cheapest in price. Anyone have any opinions/experience with the Kumho's and Continentals? Any input is appreciated. Thanks.