You won't. I flew J on QF recently as part of an EK AKL-SYD-BKK-DXB-CPT-DXB-AKL itinerary, all F except for the QF leg and the DXB-CPT leg. QF would have to be the worst business class I have ever flown. EK was in a different league (except for the purser on BKK-DXB who thought it was OK to keep patting me on the shoulder).