It really felt like a new car. The suspension was much tighter and was noticeable especially when going through turn 8 .. it was quite bumpy on the inside line but the car felt very stable and solid. It has been set-up as aggressive street...not quite at full track setup.
The R888's were quite good...I was able to outrun a stock 07 corvette that was running street tires...he actually came up to me later to ask what I was running because he couldn't believe that I smoked him in the boxster!

The instructor also commented that they were really grippy tires.
I would like to have a run at SOWs to really see how much better it feels. I have never run Big Willow before so I can't do a true comparison.