Hmm, I'm gonna be the only guy here to say I prefer a spring/shock combo over a coilover system for the street.
Most people I know with coilovers on street-driven cars hardly ever adjust the ride height. Most of them complain of knocking noises and rust issues also. The true advantage to coil-overs is the ability to corner-balance the car, for the track. Aside from height/corner-balance adjustments, a regular spring shock combo does the same thing. Most performance shocks offer adjustments for compression and rebound.
Arctic/Blk Leather/Alum.Trim/MT/ZSP/Sunshades/Blk Lines/M3 Illuminated Knob/Alcantara Performance Wheel/M-E-Brake Handle/Euro Fog Switch/Koni Yellows/H&R Sport Springs/19" VMR V718's w/PS2 Tires/M-Tech Body Kit/Carbon Fiber Spoiler/Bimmian Interior Bulbs/OEM Eye Glass Tray/SSK/Alcantara Boot/Split Armrest/OEM Dual Rear Power Outlets/Rear Ashtray Delete/OEM Alum. Pedals/Osram 6000K/Brex Rings/LED Side Markers/BMS Power Box