Swapped and stored my stock (GY LS on 309 rims) for 20 inch Yokohama S.Drive/Breyton GTS with less than 2000k on the odo. Night and day Difference. Run Flat technology is getting better in general but still can't match the ride quality of conventional high performance tires.
Couldn't be happier.
2012 650cic Space Gray/Vermillon Red/Blk.Top/Lux Seating/Heated Seats/Style 356/Apps/Prem. Sound(retired)
2012 M3 AW/FR NDH2/2MK/ZPP/ZCP/ZCW/752/6NR/+ all optionsexcept sunroof/OEM CF splitters/OEM CF mirror caps
2011 MINI CooperS BRGII/Lounge Green/Sport/Prem/Connect/Black Xenon/Black Conical Spokes/ACS springs/ACS exhaust/Alta Shorty
2012 X3 35i Titanium Silver/Black ZAP/ZPP/TECH/APPS/Breyton GTS/Continental Extreme DW (20's)