I've had Michelin Lattitude Tour HP ZP for the last 2 sets (255/50R19).
My overall experienced with this tire model has been very good. They are quiet, smooth, but yes stiff/harsh on bumps of any size. I find the stiff sidewalls are a plus when towing.

Traction and handling have been above my needs in all seasons but I don't drive like an idiot on public roadways (I get my speed jollies in a real race car). With my previous BMW's, I've always had dedicated winter/summer tires, but these Michelin's on an X5 make the benefits of dedicated-season tires not worth the trouble.

They have 38k miles on them and are at 4/32'nds. They need to be replaced in the next 2-3 months in prep for winter. If I lived in a more temperate region, I'd say they would last to 45k miles without a problem. Today we had torrential rains and at 4/32nds tread depth they handled the raing and huge puddles without drama. I would recommend the Lattitude Tour HP ZP's without hesitation to any X5 owner.

However, non-RF like the Pirelli's are over $450 cheaper per set, and I know they will ride much more comfortably and last much longer. With two kids at private universities, this represents a meaningful savings. My wife says I should just give up racing, but that's ridiculous, right?