I've got a much older pair, not sure actual age, and they are still fine but my 2015 ones there is now this kind of limpness where it squashes in a couple of mm before you get the proper firmness - kind of hard to explain.
Thank you.
Probably comparable to the padding on the 560S. I suspect that ear pads probably should be replaced more often than I guess people actually do, but it does sound like this part can last a long-time.