I have H&R Sport springs and Koni Yellow shocks and they gave my e90 a nice drop, but nothing too extreme. Looking back, I would have went with the coil overs for the adjustment aspect. Keep that in mind when you purchase, as you might want that option in the future.
BMW 2011.75 E90 ZCP M3 Jet Black | Dinan Intake/Tune/Exhaust/Underdrive/Strut Bars | Lux V4 | OSRAM 5500K CBI | 25% Tint | sitting in a storage-like state.
*M3 E90 OEM chrome grills, OEM strut bars, and OEM pulley w/ belts for sale! If interested, please send me a PM.*