QP- I tend to change out cars for the "latest and greatest" on a regular basis, as there always seems to be something better... It is at the point now where the car can't really be used to its full potential on public roads and the N55 has no currently known outstanding issues. This mitigates the craving to a certain extent.
Perhaps the only (minor) issues would be an air conditioner that seems to struggle in the Texas summer heat in a black on black on black car and some minor electrical behavior issues that I attributed to getting an early production car. While the steering is light, it is direct and I can feel the the road if I pay attention closely. It makes a great family car and is a dream on the highway, GT style. Some minor drawbacks of buying the car off the lot means not the exact options or color desired, but I got a pretty good deal on the price that no other dealer around could approach by forgoing a factory order that probably would have meant waiting for the '13 model year last summer.
Ironically, the car also has options that I never thought I would want, but add a lot of value to us, like the rear window shades. Our daughter doesn't cook so much in the back and it makes the tint look darker without compromising night time driving.
In all, it isn't a matter of not liking it but whether it proves to be fully reliable and keeps us in love with it when the new M3 or CLA AMG come streaking to the market. I would say the biggest problem is that we only have one right now and have to take turns driving it.