I don't know where you get your information but I have never, in my several decades in N scale, ever heard anyone criticize a model or a layout because the cars ride too high. The only exception is those folks on that other forum who call themselves 'asshats'. That being said, I will disagree with your original premise that, "The major problem with cars appearance is the space between the truck and the body." I would say first that it is not a problem, per se, nor is it a major issue. The major issues, appearance wise, in N scale are 9 3/4 inch curves, No.4 switches which necessitate the large coupling distance between cars. These are far more noticeable than the height of the car above the trucks.