I've just gone from Bridgestone Run Flats on the Beemer to Michelin Pilot Sport 2's and the difference is incredible. The RFT's have a very hard side wall which give a harsh ride, they are also an all round tyre. The Michelins on the other hard are giving a great ride, fabulous grip in the dry and better in the wet. They also give less road noise. So for me it's Michelins....but they are costly of course. My rear tyres are Â£242 on mytyres.co.uk... Not sure if anyone has tried these on a Zed but I reckon they would be superb.