Well, she's here !
First impressions - well I haven't had the opportunity to use it much (I will do over the weekend), but the first out of the box impressions are
1. Feels very much like my EM1 MK1 but the grip is quite a bit nicer to hold (and I thought the EM1 MK1 was good). Overall though very familiar.
2. The shutter is very quiet. Not that the EM1 was loud but this must be half as quiet again. It was like going from my D800 to the D810 - it's that much of a difference.
3. Olympus in their wisdom decided to use a 2.5mm remote jack, but I stupidly thought it might follow the same technical standards as Panasonic on my GX8 (as they also use a 2.5mm jack), but no, don't know what the difference is but a Panasonic remote doesn't work. No way I'm going to be spending £60 on an Olympus one, so I might just have to wait for aftermarket ones to come along.
4. Surprisingly, I haven't done any C-AF or shooting speed tests (these have been done to death on the web anyway), but you do notice immediately how much quicker the MK2 locks onto subjects (especially in low light) than the EM1 MK1 which was no slouch itself.
I've only done one low light shot so far (which was just a test shot) @ ISO5000, shot in raw under kitchen lights at night and developed with the Beta Camera Raw in Photoshop CC2017, but it doesn't look half bad (a little bit of noise reduction took place) but it does retain detail and DR quite well for the ISO and such a small sensor. I'm sure once I dial in my develop recipe and once Capture one Pro handles the Em1 MK2, they will potentially look even better.
Oh, and the hype over the new IBIS combined with the IS on the 12-100 isn't hype, it's true. I shot a handheld image last night at 55mm (110mm effective) at 2.7 seconds and it was tack sharp !
Anyway, that's it for now, but I'll report back when I've had opportunity to use it more and get a better feel for it.