So, I've just traveled for 7 hours by car. And to be honest, I hate long journey. But then again, I didn't have much of motion-sickness (due to car, unless I'm reading). Not sure if I have sea-sickness since I've rarely traveled by sea.
But I would say that I'd prefer flight. Though, flight is so much of a hassle and requires greater amount of money.
Quite frankly, I don't even know which mode of transport I prefer. Do you?