Flying outbound to ZRH (especially from DFW, but from JFK as well) is always a crapshoot when it comes to upgrades, as they often have last-minute full fare passengers, on occasion to fill the front cabin completely. Coming back is usually much easier to upgrade (my experiences are exclusively with VIP's), but no matter how many J seats were available, I've always been waitlisted. Make sure that if your upgrade has not cleared before the day of departure to get on the airport upgrade waiting list (separate from the advance waiting list).