This video answers a lot about EIS high. I look forward to trying this out on Monday. This guy tried out lots of APS-C L-mount lenses- I was surprised how many there are now. Also, there are some that could be amazing with that 1.43x crop in EIS high. Here's the S5i with the Sigma 10-18. I imagine this would be a cheap, great combo.
I've long thought that if Panasonic makes just a little smaller L-mount camera (FF), they'll kill M43, especially with all the APS-C lenses now available. Right now, it seems M43 only has 4k 120fps and widely available smaller lenses; the rest is practically a wash, including price.