Lowering an E90 with Xdrive

I’m not new to lowering cars, but I am new to the BMW world. I am considering lowering my 335xi and would like everyone’s advice. My car sits a little higher than most of the other E90’s due to the X Drive. My goal of this project is #1 performance and #2 looks, but I want to limit the amount stiffness.

Please provide your 2 cents and what brand springs you would recommend. Also I may install new struts at the same time, but that is something else I would like to know. I understand that stock struts can cause a reduced life with lower springs, but I am more concerned with the dampening. If the new springs are much stiffer, then they will need more dampening to compensate. I personally don’t want the springs to be too much stiffer, therefore I might not need to change the struts.

Does anyone know why BMW made the Xdrive sit higher? I can't see taking this car off-road.

Thanks in advance. Personal experiences mean everything.