I have the ProLine 750 (same phones, previous model nomenclature) and have not had a problem with the headband, only the clamping which I reduced by flexing the center portion of the headband to reduce tension.
I suppose you could try adding some padding between the headband and your head.
Or perhaps with use the headband padding will soften or your head wil toughen.
I hope it works out for you especially since you love the sound.