I'd say the performance is very good. Please do not compare an IEM to headphones, ety 6i is all about clarity. Bass is good enough, there are times where you feel there is no bass, it is because the bass was not meant to be strong in that song.
If you play the same song with other audio player and other earphones or headphones, i feel as if the bass is being manipulated out by being amplified many times so the bass comes out strong.
I did not regret getting the Ety 6i, because you can really listen to clarity of each instrument played, that is of course according to specific conditions which includes, the bitrate of the song, EQ on/off & etc.