Always enjoyable following your reasoning Jono, particularly this GAS Mark 2.0
The IBIS is staggering, and now there's the new electronic first curtain shutter to play with too.
I was disappointed with the sharpness of my old ZD 7-14mm on the E-M1, and recently got it back from Oly. I think there was something loose in the AF unit, and first impressions are it is much improved (and they only charged 34 quid!).