Here's something I wrote last month, but didn't get around to posting until just now (I had to upload the photos).
Just got my MH755 from Kanoya, and it is incredible. It's slightly better than my two other MH755s, which may be fakes, but at least one of them sounds alright too.
I paid more for mine, around $17 USD in total, which is stupid, but I wanted one with green tips. Anyway, it sounds great. Really pleasant tuning, and the fit is somehow slightly better than the others. I could wear this all day.
I'm amping it from a Fiio E10K. Usually I find it a bit overblown and heavy, but it seems to give the MH755 the power it craves.
Flutes and violins, strings in general sound natural. It's excellent for classical.
Soundstage is still limited, as expected, although in line with with cheap earbuds. Resolution is grainy on instruments compared to 12 BA monsters, but we already knew that. Percussion can be a little faint, and I'm not hearing 'ghost notes' with these. Bells sound honeyed, and not piercing.
Brass is weaker, though. It gets 'blat-ty.' A kind of noise instead of a fully-realized three-dimensional sound. The MH755 seems to do better with the higher-pitched and more treble-oriented instruments. In fact, low brass instruments seem to vibrate the housing. It seems to add some background hiss, too, in extreme cases. Low synths don't seem to have this effect, just brass.
The tuning is definitely not V-shaped. You all know it's Harman-esque. For me, it sounds more centered and rounded, or mid-centric than much of my Chi-Fi. It doesn't sound like one part of the curve dominates over the others.
It really hates noise in the original source. I have some nice tracks that were recorded from cassettes, and the hiss and pop is unbearable with the MH755. It also chokes when noise overloads a track. But it's great with clean FLAC recordings.
I'm using a $3 extension cable with it that I use with the other MH755s, it doesn't seem to affect the sound. Although I haven't tested it much.
Overall, this is great for easy listening, and as is said so frequently, you could sleep with these in-ear. You could also use them for studying, although you'd want to do the MMCX mod if you're abroad. Totally non-fatiguing. The downside is lack of detail, layering and staging that I am used to, so I guess I would have to get a Moondrop Starfield or something to beat this. The MH755 doesn't wow you with technicalities so much as it presents a coherent sound that is oriented towards what humans like. It easily passes the "don't take this out of my ears" test, which few of my IEMs can. Only CNT1, BA5, maybe King Pro sometimes, and V90 when it is doing good bass. I can lose myself for 45 minutes without noticing in the MH755.