I'm looking for a closed back headphones for Movie listening and occasionally some music as well. I'm after the closed back to keep out any background noise (should read girlfriend's music and her talking). I didn't want to spend much more than £100 and have noticed you can get the Sennheiser HD250 Mk2 for £120. How would their sound quality compare with something like the Sennheiser 600 which I know is highly regarded around these parts? Any help would be appreciated.