I only use them if I absolutely have to. I have way too much invested in my setup to put it throught the cans!
Besides, I don't get to work my TFM 55 when I use them. I had to switch to some Grado SR60's, however, prior to that I used Sennheiser HD420's, which I loved and didn't mind wearing. Never got any kind of fatigue when I used them, no matter how loud or how long I listened to them. They still work, but the band that holds the right ear piece on broke, so I can't where them anymore. Looking for a donor pair to purchase so I can swap out my working pieces. Like OCCD says - just wait long enough and you will be rewarded.