I have done since posting here.
63mm x 40mm
That is big enough, even for my FA Cup lugholes :). The complaints I've read though is that the cups are quite shallow, leading to ears like mine being squashed, and resulting in overheating after a short time. I guess I'll just try a pair and see for myself. I have tried 4 other pairs from different manufacturers and all heated my ears up beyond feeling comfortable. I just wish Sennheiser would make a pair with the same cup dimensions as my old HD555's. I can wear those for hours.
