The problem is that you have the base X-Drive suspension, the base seats, the base steering wheel, the base transmission, and the smallest brakes offered. I don't mean to be rude, but what else did you expect? I mean that's what test drives are for.
I have a rear-wheel drive 328i Sport Line with Sport Auto and my only real complaint is the lack of solid brake pedal feedback which will most likely be fixed with a stock 335i. I find the steering, seats, shifting, and suspension to be very, very good considering how little I pay a month and the breadth of abilities this car has.
2015 328i Sport Line