Cons: Soundstage is too small, Mids are muffled, Deep bass lacks volume (punch ?), Treble is not seperated enough, Overall detailless sound
after M4 & Xiaomi Piston 2, i finally got a M5 to audition. i listened it for 2 days and here's my thoughts: soundstage is the same again, small in every aspect. bass, treble, vocals, mids everything is placed just near another and the bass is too deep & powerful for this kind of soundstage. result is just bad. no detail in songs, everything sounds muffled. just like on the M4 & Piston, this is also a very bad earphone.
no need to analyse everything seperately. just switch to better models with wide soundstage, you'll instantly hear more detail both on the treble, mids & bass. narrow soundstage causes everything to drop detail. comparing the M4-M5 to each other, i think M5's 30hz deep bass response is better (and lacks some punch unfortunately due to congested soundstage again, it's something like that: body and the punch are exist together in the exact same space and lowers the overall bass quality/feeling) but months passed after i used M4, so i cannot make a 100% conclusion right now. and i feel no need to conclude about that because i'm sure from their overall potential so i'm not planning to buy them again.
just don't buy & don't listen to anyone who says they're good for anything. stay away from M4-M5 & Piston.