The adjustability is nice, but for performance purposes some would say springs are actually better, and they're like 1/2 the cost. Plus your car comes with non-adjustable springs to begin with.
I'm not saying there's anything wrong with coils, but i dont see why you wouldn't recommend springs.
Hot: 2001 Estoril M Roadster
ZCP 19's, ZHP knob, JL 8W3
Cold: 2002 TiAg M3 6mt
ZCP 19's supersports, ZHP knob, UUC short shift GROM, OEM 18's w310's,
http://absolutehid.ca hid kit