I had an K series R300 in 2004 which had 15" wheels as I felt it looked better. I now have a 420R with 13" wheels (6" on the front and 8" on the back) and it definitely rides better than my R300 did. However I didn't track my R300 and have yet to track my 420R. The 420R is, in my opinion, very easy to drive on the road thanks to the Duratecs characteristics (lots of torque etc)....with the caveat that you cannot explore the performance. As its likely to be relevant to the comments above I have 5 speed not 6. Good luck with the new car !