Finally listening to MH1C. Shortly listened to them after receiving from @
hzant6681, but didn't feel great about them. Mine says MH1C and only has the Sony name on the IEM (as mentioned by clieOS in his review), but also says produced by Sony Ericsson in the tag. Anyways, that may be irrelevant as far as SQ goes.
The cable is one of the worst I have ever encountered. It has microphonics even while wearing them over the ear. When worn over the ear, the buttons tend to get discomforting after a short while. On the plus side, the housings are smaller and yield well for an easy and good insertion. Isolation is pretty decent.
Mine is not 'burned in' barring the 30 mins I used previously. But, I guess the insertion is right this time. Also, the volume. I kept my 'normal' volume which was not enough (-35 to -40dB on RB-ed Clip+ for FX700, around -35dB for EX-1000, but closer to -30dB for MH1C).
I read that there are 'bassy' and 'not so bassy' versions of MH1 / MH1C out there. I would think mine is the not-so-bassy version. The bass is clean, extended and carries decent punch. The focus is a touch more on sub-bass on mid-bass, which hardly worries me, though in some bass heavy tracks I tried, the bass quantity feels a touch too much. IIRC, a touch less worrisome than XBA-3 did the first time. The mid-range sounds too veiled when using lower volumes, but carries decent clarity at the volume levels I am using now. The mids are warm, smooth, inoffensive with the right note weight (neither thin nor thick) though a slight bit recessed. The treble likewise is smooth, in balance with the mid range. Unfortunately, I cannot vouch for treble extension as my hearing has started to roll-off pretty early at 13.5 Khz. In this session of casual listening using Clip+ (and briefly, QA350 -> UHA6S MKI), I do not feel like missing details. The sound stage has good depth, though I don't feel it's wide - which may be because I am coming straight off sessions with EX-1000 and FX700. Separation is pretty good and imaging hasn't felt wrong. In all, an inoffensive, warm, smooth set that does nothing much wrong to my ears. When did I last write that? Probably in the Yamaha EPH-100 review. At the low end, probably Philips SHE3750?
As for the hype that MH1C beats everything high end, I can say that it clearly is not on par with EX-1000, FX700 or even HJE900 - which have been my go to IEMs for the past few days. It would be interesting to compare to several others in the 1000-3000 bracket though!
PS: Damn! It took so much time and effort to write that down. Lot of 'ring rust' as far as audio lingo is concerned.