The Sony headphones have noise cancelling and the Beyerdynamics do not, however, I've heard that the DT-770s leak very little.
I listen to electronic, alt rock and pop music, mostly in public, such as planes, buses, quiet places, etc (on my iPhone).
Suggestions are appreciated, also, if you know any other cans that don't leak, please leave a comment.
My budget is $200-350 and I currently own a FIIO E6 amp.
Thanks for all the help!