I’m curious about the interest in the “premium” GX1 and how it compares to my G3.
As far as i can tell, the GX-1 is an update to the GF-1 / GF-2 body style, but with the G3 sensor and internals. That’s the 30,000 foot view of it, anyways.
So, what are the technical differences?
The GX-1 improves on the G3 with:
- electronic level
- a bit smarter button layout
- tacky rubbery grip areas for better, um, grip
- slightly faster autofocus (0.09 sec vs. 0.1 sec for my G3)
- slightly faster frame rate and larger buffer – 4.2 fps vs. 4.0 fps, 9 frames vs. 7
The G3 boasts these features over the GX-1:
- integrated EVF
- articulating screen
- longer battery life
For fans of the GF series, I suspect the GX-1 trumps them all and should be an obvious upgrade.
For me, I could use the level and the better button layout, and I’d love the better grip. I’m not sure it’s worth swapping for, though. I think I’ll try to add some grippy faux-leather stuff to my G3 and call it good.
You can get a great price on either the GX1 or the G3 at Adorama.
Kevin Williams Photography 
How about in the memory? Are there differences in the storage capacity?
They both take SD-style cards. The GX-1 is certified for the new UHS-I class of cards. I have one in my G3 right now and it seems to work just fine, but it might be faster in the GX-1.
Slightly faster? I think I'll go for G3 for longer battery life.
Why on earth would anyone want to buy the GX1? The G3 is cheaper, almost the same size and weight, has a build in viewfinder, an articulating screen and it's almost as fast. There will be no difference in image quality either. I just don't get it. They should have started with the GX1 instead of the less interesting GF2 and GF3. The image quality of the GX1 is not much better then the earlier 12 megapixel models. Still very noisy at ISO400 and higher. The resolution is only marginally higher. I hope more effort will be made to build a micro 4/3 chip that gives us better high ISO noise results. It has been done with an APS-C sensor (the Sony NEX 5N and Fuji X100 are excellent), so why not try it with a micro 4/3 sensor.
Well, I for one is more interested in the GX1 than the G3. Smaler body and fixed screen does it for me. When I had the GF1 and on bright sunny days I thought I would want a viewfinder so I bought the X100, but I prefer to use the screen when taking pictures even on my X100. Only when I use my DSLR I prefer a viewfinder, but not on these smaller cameras. Never liked the articulated screens either, but I understand that some does. It's not a deal breaker for everyone, like some seems to think.