I just installed the 335i Eibach Pro Springs in my XI on Thursday (stock struts/shocks). They definitely tightened up the handling and took care of the excessive wheel well gap.
As far as the ride... It's definitely much firmer and rides just fine on normal, flat road conditions. But! Any good dip or bump, you'll feel for sure. Shocks bottom out easily.
Long story short... I will be ordering struts/shocks ASAP.
335 X-Drive M-sport /// AW-Blk /// JB4 Stage 2 /// 19" VMR VB3's /// Vishnu Catless DP /// CYBA Quads /// Duke Dymanics Fin Diffusor /// Amuse Style Trunk /// 15% Tint ///Matte Blk Grills /// KW V1 Coilovers /// Coded ///