I've seen a few of these performances (M1, M5, M8) on Mezzo TV and I have to say they weren't too bad. I really like Eschenbach's M6 on Ondine, as well. It seems that most Mahler performances by Eschenbach and the Orchestre de Paris are recorded for TV in high quality, so it may very well be true. And if it is, I might give the set a try...