I just replaced all four tires with Sumitomo HTR+ that I ordered from Tirerack. So far after 2,000 miles of driving, the tires are very comfortable. My ride runs a lot more smoothly, even with the lowering springs and ipd sway bars. The only thing that I have noticed (good or bad, depending on the driver) is that the sidewalls on these tires are soft. When making sharp turns, you feel as though you don't have control of the car, even though the car would still stick to the road and make the turn...i guess it's just the feeling of being in "control" factor. These tires were pretty cheap from Tire Rack ($84.00/each)

Before I changed to Sumitomos, I was running Bridgestone Potenza RE730...I think they are named RE750s now. They run about $140.00 and up and lasted for over 35,000 miles or 2 1/2 years. Also great tires, but the ride was harsher. Hard sidewalls, which made you feel as if you had control of every turn.

On a side note is that the Sumitomo is an All-Season Tire and that the life rating is a little higher than the Bridgestones (360 vs. 320)

Hope this helps!