i paid £215, my b-pillars started cracking and i blame it on the suspension kit, but many, many people have fitted suspension kits and it has not happened to them, but it was the only reason i could think of for mine to start going
you wont be able to get a full car loads with it lowered and 15's
it definetly handles a lot better and becomes a little bit more predictable round corners
mine went with the car, i cocked up putting it on, so once it was on it had to stay on