Glad you mentioned this. I found my pads were not locked in to the correct position; they were easy to rotate, so I removed them and installed them with the thinner side toward the front and also locked in place. Now they don't rotate. I am assuming this is how they are supposed to be oriented - with the thick side at the rear of the head.
Something else curious - my HE-500 is slightly more sensitive for a given volume setting. I had to turn up the volume on my (very modified) HEED Canamp ever so slightly for the HE-560. I wonder if this is because they need time to break in. They have the same flatness of soundstage dimension and lack of dynamics that my HE-500 had when new. This is all relative since in general the sound is wonderful. I fully expect they will change after the requisite break in period.
And yes, they are comfortable headphones! (If it weren't for my right ear touching the driver I'd be quite happy!)