What does m4/3 do that the Sony RX100 can't? What am I missing?

Not on my copy at least. Blowing highlight is a matter of settings and metering, I did not find this to be an issue on the RX100.

Do you have any example of "Significant rolling shutter" ? I cannot see that on the short clips I took up to now.

--

http://www.flickr.com/photos/ensh/