I'm SG wife is SS, had 2 op ups for her Y to J, she wont pay for J (but I do), she says better to have difference to spend at other end. Last time was HKG/CNS on CX, we separated at gate, waved goodbye, later as I was putting my gear in upper bin, I had this sixth sense, looked over the other side of the cabin and there she was getting all comfy in her J seat.