It is definately the way to go if you are hauling large items on a regular basis (like surfboards) and still want good fuel economy. Otherwise, I see no benefit. With regard to the suitcase thing, I would put all of my stuff in two small suitcases that fit in the trunk of a 135i coupe instead of one big suitcase.

It is funny how everyone complains that BMW are getting too big, then when BMW makes a smaller car the same people complain that they cant haul a ton of stuff in the little trunk.