As a long time 4/3s user, I had gotten used to a certain level of 'background' noise in my photos, and I think I got pretty good at noise control. I think I had 4/3s noise "under control".
However my new E-M10 is really quite good when it comes to noise. I rarely shoot at iso levels greater than 800, and noise simply isn't an issue. If it is there, it is a touch of luminance noise that is either pleasant to look at or easily removed with the simplest of anti-noise controls. Color noise simply doesn't exist except under extreme situations. (For instance, a well lit outdoor scene where you want to show some detail inside a window of a bldg.)
See my previous post on a hint for noise control, HERE.
I'm getting to the point now, where I leave a bit of luminance noise in the photo. Not much, j u u s s t t enough to add some texture to the bokeh areas and large patches of a single color.