on carpet Im running the 2,5mm - but my new set up is so different from the set-up on the 2,25 that i cant say the difference on the chassis only.
but car is still handling great, precise and fast.
New changes are
9,5T LRP Brushless
C/C Xa/E
and Hara springs "SuperHard" front and "Hard" back
otherwise everything is in accordance to Gilles DHI set-up
Running 9,5T - taking out the steering screw in the top deck gives to much steering....my 5€