Diane:
My impressions after a few days;
I've been quite surprised by how effective the IBIS is, much better than the OIS in my lenses.
I think the ergonomics, without the grip, are similar to the G3, from what I recall.
The OM-D's EVF and LCD are better, the touch screen is great, but I do miss having a fully articulated LCD.
I hated the menu setup the first day; I can tolerate it now; and it should be OK once I save some custom configurations.
About IQ, I've been comparing it to the G1 output. The OM-D is better, but with good light and proper exposure, the G1 does surprising well up to ISO 400. Differences were greater at higher ISO. These were RAW files processed in LR 4.1
Your G3 has much better IQ than the G1, so I'm not sure that IQ alone would be enough to upgrade to the Olympus. You're being wise to wait for Photokina and see what comes up.
Cheers,
Santo
I've had the GH2 and G3 since they came out, and have now had the OMD for 3 weeks.
The image quality difference between the 3 is minimal; I'd say 1/2 stop extra dynamic range and 1/2 stop difference in noise behaviour. I got it mainly for the IBIS, which makes my Leica lenses from 35mm on up useable, and makes the 12, 20, 45 and 7-14 more useable. Ergonomically, I still like the GH2 better, but the OMD is better than the G3 and much more customizable, of course. The menus on the OMD are poorer than the Panasonics, mostly because a lot of the options on the OMD are not discoverable or fathomable without the manual or other help. Once it's set up, it's fine but I always have the manual with me on my iPhone.
The IBIS works very well at short to medium focal lengths, but the Panasonics OIS is certainly better at the longer tele lengths, which makes sense.
I really don't like the screen always being out; the rotating screen on the Panasonics is much more to my liking. I find the OMD touch screen very hard to use; the sensitivity of the Panasonics is much better but wouldn't work for me unless I can flip the screen. The screen and EVF quality is a bit better than the Panasonics, but not enough to matter to me.
One of the things I like most about the OMD is the highlight/shadow display in the viewfinder, which makes optimal exposure a snap and will definitely make the most of the image quality available. Digital having made me very afraid of highlight clipping has caused me to often underexpose on the Panasonics, which won't be the case on the OMD.
All in all I'm very happy with the OMD, but as far as image quality is concerned, I don't see a need to go from the current Panasonics to the Olympus. I only shoot raw and have profiled all my cameras, so the colour quality is pretty much the same.
Henning