Listening to a set of Beyerdynamic Amiron -> Chord Mojo -> Panasonic SL-CT820 was the best "portable" listening I've ever heard... I think some of the high-end Sony Walkman and Astell&Kern players are in that territory, but they've never appealed to me.
They would be less cumbersome, though. It might take a while for wireless audio to reach the same heights.