BA kindly upgraded myself and Mrs TN from WT to WT+ DXB-LHR a few weeks ago and I have to say it was a lot better than WT. The quiet was the main thing I noticed as well as the increase in comfort. I would definitely consider WT+ as a paying customer but it all depends on the price difference to economy. The thing is - you don't get there any quicker in the premium cabins - you did with Concorde and that's why people used it.
TN