I said previously that when you consider the complete flight experience (including airport transfer) I thought that EK's economy class had the edge over EY and QR. However, 3 of my 4 recent legs with EK were on newish and half-full 777's. If each leg had been as uncomfortable as the packed LGW-DXB flight on an older 777 then I would have felt very different about the experience.
If the new DOH ever opens, I think QR will have the beating of EK, price and available destinations notwithstanding.