Sony X or Hifiman 602

Holding them both, and I personally would recommend the hifiman602. They both have excellent SQ, but 602 has a more warmer and richer mids which Is my favourite. So if you enjoy this style like I do, you will definitely like it. However, other than sound, 602 doesn't has such decent design & UI as Sony X, and you should aware that it is three times thick than the sony X. So upgrade or not, it's really up to you:)

Yes, it support Flac format, but it do not support AAC.

 I haven't heard the hm-602, but i do own both the hm-801 and sony x1050 and i would say that the sound quality seems so much better (still burning in the game amp for my iems) than  the sony, but it loses on lot's of other things. Like hitmanx said, the hm-602  is thicker and thus less portable. It doesn't have  a playlist feature (besides a cue list that only works on a single flac file) and it can't play video's or pictures and no wifi.

The only thing that you can gain from this is a better soundquality in exchange for lot's of features lost compared to the sony, but i still like my hm-801 though.

Edited by Hyl - 10/23/10 at 1:25pm

As a 602 owner I can concur with what's already been said. If I can elaborate on one point: the 602 doesn't have much fluff (some call features) but what it does, it does extremely well, and that's play music extremely well. Great actually, and high res files to boot! That's why I bought it! If it fits your lifestyle or aesthetic it's pretty darn good.