I'm a little confused with suspension, I want to get coilovers I was thinking Tein HAs or RAs. My friend told me coilovers suck, he has koni yellows, skunk 2 adj coilovers on his Si. He says adjustable coilovers suck. I'm a little bit confused exactly on what a coilover is, what's the difference from buying springs or something else. If someone could give me a quick overview of suspension that would be great, I want the best handling for my car but not knock my teeth out when I hit a bump. Thanks.