Curious if there is any experience out there running the "ZP" (zero pressure) version of the Latitude HP? I'm thinking about going there but am a little concerned about the 'harsher' ride. I'm a BMW owner as well and frankly enjoy a little more feel than my Conti 4x4's are giving me (on 18'' wheels). I believe the HP ZP is begin put on the X5 as std equipment (sometimes at least!) so I thought I would give 'em a try. Believe it or not, the ZP's are selling for $189 on TireRack right now (reg HP is $222), aren't the run flats usually more expensive?

Anyway, I would appreciate any comments regarding the ZP, thanks.