(My previous attempts to post this seem to have gone wrong somehow. If they do turn up later, I'll come back and edit the redundant posts.)
Even though I am generally comfortable in my 497s, I do notice that after a long listening session the cartilage in my right ear gets a little bit raw. (My ears may be shaped differently from each other.) Not screaming agony, and not enough to make we want to return them or resort to a basketball, just a bit of rawness.
Here is what I did to solve this problem for myself. If any of you are having just a slight comfort problem with your 497s, try this:
1. Get two small pieces of thick paper towel, cheesecloth, foam, or etc., and roll each piece into a sphere the size of a small gumball.
2. Put on your phones.
3. Stuff the material behind your earlobe, so that you fill the gap between the side of your head and the earcup. You'll feel the pressure lift from your ear as the material gently pushes the bottom of the earcup a bit outward. This does not seem to affect the sound quality, but it does allow the material to take the brunt of the pressure from the earcups. I imagine that wearing your phones this way all the time would eventually stretch the headband into the final desired position for maximum comfort, without the risk of over-stretching them.
I will rephrase it. What I do is, I roll up two little wads of paper towel or other similar material, then once I have the 497s on, I stuff those two little wads behind each earlobe, underneath the bottom-rear edge of the earcups pads (obviously, for this to be possible, the earcups need to extend as low as your earlobes, which may not be true for some people). This lifts the bottom rear of each earcup slightly off the ear/away from the head -- just a few millimeters difference, not enough to change the sound or anything, but it takes just enough pressure off my ears that the inside of the earcups no longer press against the cartilage in my ears.
It's the same general effect as if you had simply hooked your thumbs underneath the bottom-rear of each earcup and pushed the earcups outward slightly. You're stretching the headband just as the basketball would, only temporarily and by a tiny margin while actually wearing the phones.
Actually, as my 497s get more accustomed to my head, I'm starting to find even this step unnecessary.