I've been looking back at a lot of photos from the past few years today (one of the perks of being sick with a cold is that's about all I'm good for right now). The thing that struck me was that while the quality of my 'good light' photos has basically remained constant since I got my first 10MP DSLR, the quality of the 'low light' photos has tended to vary dramatically. The biggest gain I saw was switching to full frame from an 4/3 DSLR in 2008. I went from having barely acceptable ISO 800, to generally acceptable ISO 6400, and that, combined with an f/2.8 zoom and f/1.8 prime, really made the difference when photographing indoors. Of course, now that the E-M5 is my main camera, I make a big effort to limit high ISO to 1600, which can be challenging in low light, and is downright impossible unless I'm using prime lenses. Usable ISO 6400 or even 3200 would make a big difference. There aren't that many sites that give good high ISO tests (far too many rely on in-camera JPEGs and other nonsense), so for all its flaws, I've tended to rely on DxO for my high ISO metrics. Indeed, it confirms my current experience - that there's about a 1 1/2 stop gap in noise between the E-M5 and my old D700. Now 1.5EV is quite a gap - bigger indeed than the gap between Olympus's top-of-the-line in 2007 (the E-3) and their current top-of-the-line (the E-M1). So the question is - when will m4/3 reach the point of sufficiency for you on high ISO? And do you think it likely that we will see a 1+ stop improvement in the next generation?