They are rather comfortable, even if they make your ears hot after half an hour... This is true that they are less effective than other pads, but you can mod them the same way we do for the 414 pads (yellow).
I just received my bowls and flats pairs today, and frankly I can't tell which one I prefer : they both give new perspectives to my MS-1. Same thing as usual :
Bowls : more clear and detailled, less muddy and more dynamic bass
Flats : More full and generous bass, energetic mids.
But I like them both, they are complementary. The next week I'll know if I can get 2 pairs of 414 and mod one of them. Many people on the forum say that 414 are the extra low-price comfort and bass mod.
About conmfort on Bowls and Flats : bowls are not so harch for me, nor the flats.
I don't think it is a good idea to get the driver too close from you ears, you won't win very much. Flats, Bowls and modded other pads are opened to the driver and that's enough to free the sound you were loosing (not that much, don't worry).
Flats are the closest from the drivers. What is curious is that you can listen at a rather loud volume with less fatigue to your ears than with the comfies at a bit lower volume. And it is fairly great. Furthermore you don't need to use a high volume to have a good sound. With bowls you have to push them a bit more.