Mine are both floppy. I think it makes them look much more clownish and fun loving, more like a loveable family dog. IMO cropped ears make a dog look more like a guard dog, more fierce. I'm not saying that cropped ears mean that they are fierce, just give off that persona.
I love boxers and would take one in any way shape or form. I feel it is a personal choice as to the owner's preference of what look they like and wether or not they are able to have it done.