I've flown (and family members have flown) GVA a number of times. Between the swiss traveling on holiday (easter end of march?), switzerland loving south asians and gulfies, and private bankers making their rounds, it's a pretty full flight.

I have, however, been op-up'd a couple of times Y to J (Gold) as the Y cabin is especially full. So you never know day-of... but a D seat opening up may indeed by a pixie dust.