Do you think the A700X is worth the extra £60?For the use you describe, I definately go for the Audio Technica. It is the best sub £200 headphone I've seen in years. The amount of sound it leaks shouldn't be an issue unless your significant other is really picky. I've used the £220 A700X as well and that is sensational.
The Beyerdynamic is a superb all rounder but if you don't want to use them on the move, you don't really need that.