Often on CC I see a lot of sales in which F&F Coils are cheaper. And the warranty for CS-II coils are only offered on the Street set. So if you were planning on doing some track and heavier spirited driving and getting the Sport set, then the warranty is not included.
Cheaper than $560 shipped? Even if they were $400 I still wouldn't buy them..
I'd say maybe about <5% of the people on this forum would ever do a track event or NEED stiffer springs and/or biased spring rates to the rear. Even less would benefit from it. I'd never suggest a novice to run the spring rates that Progress lists as their "Road Race/Autocross" setup, esp if the car is driven on the street. So what I'm saying is, the spring rates that Progress offers for their "street" setup is more than enough to have a fun car that even has the potential to do well on a road course or at an autox event.
Which BTW, I'd never run Function & Form coilovers for any sort of motorsports competition. There's a reason that in my 6 years of autoxing and being around tracks/drivers that I've never seen Function & Form used. The serious competitors(IE: National Champs) sure as hell don't use their products. Yet I've seen and heard Progress time and time again.
Just saying.. Buy what you want.