Ian, They're alot firmer than the S tunes for sure. I have had them in and did maybe 100 kms but 36 hours before the Nats I had to pull them back out . I don't really drive the car that often on the street so I spose I can put up with it a little. The S tunes are great on the street but feel a little lack luster on the track. The R tune spring rates are 12 F and 10 R IIRC, so yeah, firm.
Just wait till this years nats, i'll chuck you the keys and see if you like them or not.
Annddd the rears are in