I don't know what it is, but the timing on some of the notes just seems off. Like if some notes are 1 ms before the song and others are 1 or 2 after the song. Inconsistent timing is the best I can think to describe it. It's most apparent in the first minute of the map.
I can agree with that. Difference is very small either way. It shouldn't affect scores unless the player is already right on the edge of getting a 100. I'd also like to see other opinions, but I don't want to keep this from ranked just because of a small timing preference.
I think the sliders at 00:21:746, 00:30:390 and 02:38:018 sound a little off, maybe a little too early. This seems to go away if local offset is set to +3ms while listening with the auto mod.