... yeah I tried it once with my Rhino '06 20m and it sucked. Mind you, I could ride upwind (sort of) and with kite at the edge of the window, forward loop it and you wouldn't miss a beat still going upwind. All that room for even a slow turning kite, was easy to do.
Delayed steering and not as good upwind was the glaring results, infact there really was nothing gained in the exercise. I'm sure you could design a kite with 50/60m lines that would work then maybe its an advantage but not with kites designed around 20/25m lines.
Anyway, do it for the fun of it, give it a go.
cheers
Robbie