The knock on the micro four thirds camera system is that it sucks in low light photography. I would suggest that that this assessment is incorrect for all but the most strident full-frame professional photographers.
I used my Lumix G9 to take photographs of the most awfully lit play facility this past weekend and got plenty of fabulous photographs of my daughter and her fellow cast mates. I am about as far removed from being a pro as one could get but there were no complaints of the quality of the photos I provided to the homeschool group. There might have been some grumblings about the quantity of certain individuals but my audience was quite taken by the photos I provided.
The interesting thing about low light noise is that it is pretty easy to clear up in post-processing. As long as the image itself is sharp and crisp then diving into Lightroom and de-noising the photos will help quite a bit. Sure you probably won’t be submitting it to a magazine but for most enthusiast photographer the image will look just fine.
With the G9 I try not to go above 1600 ISO. Now, a low light beast like Sony’s A series or a Nikon $3,000 model or similar from Canon will let you shoot into the thousands for ISO. I don’t really care. I mean, I don’t shoot in low light that much and the times that I need to like at the play the micro 4/3 system works just fine.
The great thing about the G9 is the image stabilization is good enough where I don’t necessarily have to use a tripod. I didn’t for the play and few photos I took were blurry. Sure, when the subject made quick movements the photo turned out awful because I wasn’t able to adjust the shutter speed much faster than 1/30 of a second at any time during the play, even using a fast f/2.8 lens.
So if you are concerned about the low light capabilities of the G9 then you really need to consider what you goal is for photography. If you are a pro then I guess you will be bouncing around between the various full-frame gizmos for your purposes. If you are hobbyist or enthusiast and are considering a micro 4/3 camera then I wouldn’t let the chatter form pros dissuade you away from the G9. It is quite good when the lights are turned down.