I owned and returned a pair of Denon D7000's because they could not keep sound in. At medium-high levels of volume they leaked like a sieve and almost sounded like open cans to me.
SoundFreaq, just how well do the Signature Pro isolate? I share an office at work and have not been able to find a nice pair of closed cans that I can use here with how loud I ten to listen to music. Currently I fall back to my UM3X's but really want to move over to the full sized headphones when i am in the office just for ease of taking on and off when needed.