i have a set and they suck for everything other than lowering your car and stiffening up your suspension. I got em used off of a guy on here and i got em for cheap, i think they were already blown tho. They are really stiff but I believe the spring rates are 12K and 10K (front and rear) which is pretty damn stiff...coupled with blown struts, well the ride isn't stable over bumps.
as far as lowering the car the fronts can go really low(probably another inch at least before hitting the collars but the rears don't wanna go that low. I lowered my spring perch quite a bit just to get it this low in the rear which is about as low as i wanna go anyway but for some reason the rear coils have a longer shock body or something. I know a few people with the newer models(red ones w/ dual ride height adjustability) and they go really low without having to drop the spring perch, my buddy was tucking SE wheels on his s14 and draggin frame rails lol
crappy pic but you get the idea
**i paid 200 for these and they do what i want for now, will I pay the 5-600 bucks for them off ebay? NO, I'd rather save up another 2-4 weeks and go with Powered by MAX, DMAX, or Fortune Auto which are proven coilovers. Sure they are double the price but they will probably last you more than twice as long, just my .02