Very thoughtful review, thanks for the effort. I strongly disagree, however, that the HM-801 "doesn't get unbalanced in low volume." With high-sensitivity custom IEMs and the standard amp module, it's very hard to get a comfortable low volume in a quiet environment without channel imbalance. The GAME card is only a little better in this respect. Hopefully, Fang is working on how to make the gain not jump so quickly with each touch of the volume pot.
I guess this need a bit explanation: by low volume, I really mean low listening volume. In my case, 16 ohm IEM (i.e. CX300) does have a little imbalance in the first few degree of the pot, but it is still lower than what I consider my minimum listening volume. Same goes for my UM2 (27ohm).For the majority of IEM and headphone I tested (all 32 ohm and above), I can't say there is imbalance beyond the first two or three degree of pot and it has no effect on minimum listening volume. I don't have any custom, so I won't know how they behave.
Another problem I've noted, and which I'm surprised that more people don't complain about, is the high-pitched ringing sound that I hear whenever I pick up the HM-801 or touch it around the top of the player. It seems like touching that area causes some kind of feedback, it sounds like bad microphone feedback. I thought it would only be a problem with sensitive custom IEMs, but I hear the noise very clearly with my full-size Edition 8s. (This is only a problem when using the internal amp, the noise doesn't occur when using the line-out to an external amp.)
I don't have that issue with mine.
As for .cue files being the answer to gapless playback, I haven't gotten them to work. When I open a .cue file, I see the different songs, but I'm not able to skip around within the continuous file to different songs. Whenever I try to fast forward or skip to the next song, it simply skips back to the beginning of the entire mix.
Thanks for pointing that out. As I have mentioned in the OP, I don't really have anything that need to be gapless, so I didn't test the cue function myself. I'll try to find something to play with and try to confirm your result.