Does it hum? It does when you put near your ears it's like a very soft breeze (looks like something is continuously running inside) though not audible while shooting
How does it feel in hand? I'm medium sized gloves and I find it easy to hold , the padded thumb rest is like a thumbs up feel
Too small? Not really for me actually sleek
Is the user interface good, or unbearable like on the E-P1? (sold mine because of that) UI is easy and simple, used it without reading the manual no problem
Focus fast and accurate? Oh yeah focus is very fast not really tested the accuracy but looks like it is
Have you tried any manual lenses yet? Nope and I don't intend to use manual focus lenses I have other RF for that purpose
EVF? EVF is IMO a bit better than the EVF-2 which I also used with my EP3
and most importantly, are you happy with it? Initial impression I can say I'm very happy
I can't wait to get mine.