In reply to The Lemming:
> Yes the sensor is smaller than my Nikon DX sensor, however the image quality is just jaw droppingly stunning and pin sharp.
What lens did you have on it?
> The landscape shots are also breath taking. And the Bokeh, I hear you cry?
Bokeh as good as or better than my dSLR?
Lack of Bokeh is the thing people moan about - I guess it depends on how much you need shallow DoF to isolate your subjects.
> And more importantly, its a heck of a lot lighter around my neck. But, Would I have been happier with a full frame mirror-less camera? Probably not for two reasons, the first of which I could not justify the cost and the second would be that I'd have to do some extreme pixel peeping to even notice the difference. A big thank you to everybody who owns a Micro four thirds camera for recommending that I give them a try because they have most definitely come of age.
You're welcome. They still have their limitations. Although I've not ever used anything with a larger sensor I find the following issues with my E-M5. I class them as issues because they frustrate me - I might have the same issues with a larger sensor camera, but as I don't have one I can't tell.
1) tracking focus - if I try to shoot my toddler running around the garden the tracking box will randomly stop following her.
2) astro and low light - noise is an issue when the ISO is high enough (3200) to allow a fast enough shutter to prevent motion blur. Not a major issue with an f1.7 lens, but is with my f4-5.6 zoom. You will need the <f2.8 lenses to shoot things like weddings and parties without a flash.
I'm still generally happy with mine - the small size is great for taking everywhere. You said it blew you D5000 out the water - have you tried a more modern APS-C or FF camera to see what they do?