I have been with my HM601 for the last 2 wks, and I have to say I absolutely love this player. Battery life aside, useless UI, slight bulk, finishing that loves dust and fingerprints, pathetic internal storage, plus I can't seem to fast forward individual tracks ... etc all this may sound like a huge waste of money and a disgusting con job by HIFIMAN. However for a portable player that is of the same size as an IQUBE amp or SR71a. I think it is great. I have been comparing this rig to a ipod classic with both the iqube and sr71a portable amplifiers, and I love the warmth and presence of the sound this player produces. I feel that it betters an ipod with any portable amp, probably due to the ipod itself as a transport.
I have also been comparing the HM601 with an IMOD rig with external VCAPS and also amps like the SR71a and the IQUBE. I feel that the HM601 can stand it's ground with the IMOD rigs too. It is not that the IMOD/VCAPS/AMP setup is bad, however this kind of setup renders your portable into more of a transportable category, which you will never ever be able to squeeze into a pocket. Sound wise I do prefer the big IMOD rigs (just by a bit), but then again I'd better as those guys are at least 5 times the price of a HM601 and about 3 times bigger. Sound wise I do find that the IMODS portray/ render/ produce sound in their own particular way. Slightly more clinical and better for analytical listening. The HM601 produces a colored sound that is warmer, lush and engaging, that makes listening to music more enjoyable. This is also not to say that the HM601 isn't a detailed player. IMHO the player presents all the details of the music in it's own special almost "hifimanish," way.
I think if you already have a good quality IMOD transport and are strapped for cash, you can just look elsewhere and save your money. If you are looking for a good sounding player, for much less monies than an IQUBE amp, this player is something to consider. Do note that at the end of the day, pursuing the headphone hobby is expensive, and reviews/comments are very much based on individual preferences, which may be as varied as religious views. The best is to find someone who lives close to you and have a try to make your own decisions.