It depends on what you want i would day, if youre looking at flying with an airline which doesnt treat its employees very well then by all means fly QA, as you will always see the crew smile, as they are most than likely forced to smile or threatned with termination if they dont :), i have always flown Emirates and till today have had no complains with them, the only problem would be the transit in Dubai, a pretty busy airport. Else your could always use BA they use a 747 from Doha to London if i am not mistaken.
But thinking about it, you would have to use the same airport to check in anyway, 5 star service doesnt just start when the plane doors closes, its the whole package from when u would start your journey, and with QA i dont see that happening, the airport is dreadful, they treat most people there like a herd of cows which are going to be packed into a sardine can.
Emirates may not be a 5 Star rated airline but if you read in among the grading of the airlines your can actually pick out which one is a better one, emirates has been operating much longer than QA, their inflight entertainment is the best in its class, no other airline can come close, their are the trend setter.