Initially during testing the 06+ Civic SI shifter is much smoother then the RSX. However the shifter felt very light and hard to be able to locate the correct gears during spirited driving. Therefore we are currently looking for local 06+ Civic SI vehicles for more testing and reviews. We have a vehicle already tested with the prototype sports shift springs but looking for more vehicles to review our great products. Please reach me at the contact page and we will work out something.