To be fair, my KW V1s are cranked all the way down, and the ride is very rough/tight. I've been told that if you keep it higher at stock suspension height, it's more comfortable, but I've always been slammed on these things, and they're not comfortable at all.
You also have to consider that coilovers are less durable than the stock suspension. Coilovers are built for the track, while stock suspension is built for the road. If you mainly drive on bad city roads, expect your coilovers to wear prematurely. My friend who lived in an area with bad roads had his KW V3s go out on him within 15K miles.
E92 328xi | KW | AA | LUX | OEM 359M | BMW Performance Exhaust