Luxury line doesn't have the lowered suspension where sports line does.
Also need to consider if you want the car to be sportier or more comfortable depending on what you prefer.
This is more than just the seat
I had sports seats in my E86 Z4 and E92 335 coupe, I don't really drive my F30 328 sedan hard enough to need that.
You may also find the larger dimensions of the car make you not turn as hard as an E92.