Ha, when I clicked on this thread I had the Bordeaux lounge in mind, and bingo that was the one that kicked if off!
I used it in January (fancied a day trip thanks to that super low fare in the January sale), and it is really little more than a glorified waiting area. It didn't help that the flight was delayed by more than an hour.
I didn't complain because I wasn't really bothered at the time, but I expect if you did you would get offered a few thousand Avios or so.