[Klaus]

The ZX1 (or the LX100) isn't any more compact than similar system cameras really. At least there's no technical reason that I can think of (give or take a few mm).

I still maintain compactness of camera + lens is an advantage.
The LX100 lens is 24-70 equiv and f1.7-2.8. What MFT zoom can match it in terms of size and speed? (even if you consider the 2.2x crop factor vs 2x for MFT)

I suspect that you could develop a similar lens for MFT really. Probably took advantage of a bigger opening on the LX100 there but a f/2.8-4 would certainly be possible.