I currently have a Panasonic G3 and I am very happy with the IQ. I am mainly using the Leica 25 1.4 lens and the 14-45. I do have a couple of complaints though. First, I wish the grip was just a little larger. It is not easy to keep a solid hold on the camera. And then secondly, some of the controls could be better. The wheel is a little small and it doesn't feel all that solid; and then I wish you could make more adjustments without having to go into the menus. So, I am considering replacing the G3 with either a GX1 or a GH2.
Here are my thoughts on the two:
1. So far I haven't used the EVF on the G3 so I suspect it is not that important to me. Although I should say that I haven't shot outside in bright light so once I do I may change my tune on this one. But I do feel a bit more connected to my subjects when using the back screen vs the viewfinder.
2. I like the idea of the smaller GX1 but it would be important to me for the grip to be a bit larger and more comfortable / solid than the G3. If there is not much difference in this area than I probably would pass on this camera.
3. I would like just few more external controls on the camera and the GX1 metal buttons are appealing to me. I like the feel of a solid, quality camera.
4. In reality, the size of either will probably be OK for me as my other system is a Canon 5D II with large lenses so either will be substantially smaller than that camera.
5. I don't believe the rotating LCD is all that important to me.
6. Finally, the GX1 is appealing since I can buy another lens at a discount with the bundle deal!!
Let me know if you have other questions. Thanks for your input and recommendations!
I have owned the GH2 since December of 2010 and the GX1 for a month. I have not handled the G3, but the GX1 grip is pretty sure for a small camera, but I don't think it's significantly different from the G3's grip (though it's a smaller camera, so it may feel better to you). The GH2 grip is very secure, and is a big step up in handling, especially with larger lenses, provided the size is not an issue for you.
The GH2 has more external controls than the GX1, but the metal buttons do feel better on the GX1. They're nice. The GX1 handles extremely well for a small camera, but it lacks the dedicated switches for drive mode and autofocus that the GH2 has. One nice thing about the GX1, though is that the quick menu is better implemented and it has an internal orientation sensor, so your verticals will all rotate properly. It's nice.
The GH2's viewfinder is slightly larger than the G3's or the GX1's external EVF, at least when shooting 3:2 or 16:9. Also, unlike the G3, it has an eye sensor so it automatically switches between the rear LCD and EVF, which is very nice.
The GH2 has a multi-aspect sensor, which is great if you shoot other than 4:3, as you don't get a cropped image in 3:2 or 16:9...you actually get greater horizontal FOV and decreased vertical FOV.
The GX1 is better at high ISO, with a little lower noise and much better color response and dynamic range at 3200 and higher.
The GH2 has much better control over video. The GX1 has the ability to basically set ISO and, well, that's about it. If you shoot a lot of video, the GH2 would be the way to go.
I own both and use both. If compact size and a little better software and a little better high ISO image quality are your desires, then the GX1 would be the way to go. If you want a bigger grip, EVF and multi-aspect sensor, or if you're shooting a lot of video, the GH2 is the way to go. The GX1 feels more solidly built, but the GH2 has held up beautifully for me over the past year+...I've put about 17,000 frames on it in a year and two months. The GX1 feels like a small rangefinder and handles best with small lenses like pancakes or small primes like the silver Olympus primes (12/2 and 45/1.8). The Leica 25/1.4 also feels fine on the GX1, though larger lenses start to feel a little awkward. The GH2 feels like a small DSLR and handles well with pretty much any lens.
For a comparison of G3 vs GX1 grip, take a look at this, and switch the views for each camera (the little widget at the left) for the top view for both cameras. Looks like the G3 and GX1 grips are extremely similar, with the GX1 grip being a tiny bit smaller: http://camerasize.com/compare/#185,183
The site is being weird right now, though, so if it takes forever or loads odd images, give it a bit (it was giving me a Nikon image for the GX1 a few times.)
I have the g3 and a gf1. If gh2, g3, gx1 are your only options and you need a bigger grip, then gh2 is your only other choice. I have a 5d. If you will shoot the panny outside, you will eventually need the viewfinder. Once you add the viewfinder to the gx1, you wind up with a system similar to the g3 but much more expensive. So you can buy more glass if you find your lenses lacking.
Trade offs....
The GX1's video is pretty good, but it's not the camera to get if you are a dedicated video shooter (or even if you plan to use the camera for significant amounts of video. Mainly because it doesn't have the control over video that you get in something like the GH2.
It's an excellent camera for stills, though, and good for movies provided you aren't making serious films...image quality is pretty good for the most part in filming, but the lack of controls means I tend to do most video shooting with my GH2.
