The Grand Carrera Pendulum is basically the GC Calibre 11 with a tourbillon. In the gen, and this is argued, it would keep more accurate time. In a rep, as I suspect is actually true in the gen too, it would be strictly aesthetic. The Calibre 11s are not terribly accurate anyway due to the sweeping second hand. I happen to think the GCP is quite good looking. If you can find a good rep, I say pull the trigger!