I had WAW-DOH-PVG booked on QR in J. How delighted I was when the positioning LHR-WAW was changed to QR. I paid £120 to upgrade to J for the experience outbound which beat CE hands down in terms of service, friendliness of staff and meal selection. I'd selected Y exit row on the way back but didn't think to check the effects of the equipment change but had sufficient legroom in 10C - cushioned seat was lovely.