I took that hovercraft several times. As I remember it, the inside was full of cars, and the pax sat on the outside. You couldn't see much out of the windows because the spray covered them most of the journey, but I remember them as bucking like a bronco rather than slowly lurching. And they were noisy.
It might even be economical to bring them back, as although they drank fuel, the price of using the Channel Tunnel is now so exorbitant that they might be economically viable again. I'd rather see them come back that the subject of this thread replace the ferry.