Upload & Sell: Off
G3 has very nice noise performance for a small package. I have not used the Nikon.
Some things I note from a year of use-
It is a relative bargin when purchased used.
It goes in a jacket pocket or small fanny pack. It does not go in a regular pocket.
You will not have have the equivalent of ai servo unless your lens has image stabilization (the 20mm pancake does not). However you can have it track an object in the frame if you get it to lock on. This is nice for faces that move like toddlers or candids and mitigates the lack of an AI servo with the 20mm pancake.
Face detection is great for when others take a photograph of you and don't know how to focus.
Writing a raw image to the memory card is slow and you have to wait on that before the next click. Shutter lag is mildly slow. Hence, if you are trying to catch a transient smile or part of action it can be frustrating.
I think if it were not for the 20mm pancake, I'd have never purchased this as my sidekick where it proves very useful for family photos when I have a specialty lens on the 5D. You just can't take a good family photo with a 400mm lens. Anything bigger than that and I might as well take my 5D and 50mm 1.8.
I need the OVF and did not want to pay extra for the GX1 with OVF which becomes about the same size at that point.
I used to take my G3 out more by itself, but I tend more and more to just grab the 5D and 50mm 1.8.
If you are not needing super low light performance from a fast lens, have you considered the RX100? It is pricier as newly released, but apparently shirt pocketable.