They are bad. I have medium-large ears and with the stock "bowls" that the HF-2 come with I can't stand them for more than a half hour. My roommate has small ears and can wear his SR-60s (or SR-80s, can't remember) with the "comfies" for hours.
I had the HD 650s two years ago and they were amazingly comfortable. They would disappear on my ears. Very non-fatiguing sound signature as well. The HD 650s would be a night-and-day difference with any Grado when it comes down to comfort.
Sent from the Scarlet Devil Mansion.