Well, I was very happy with the quality of the e-m5, especially with the 45 1.8 and the 75mm. But then I looked at the A7r....
I guess you really can't have it all.
I have a picture of a glacial moraine taken almost ten years ago with my Olympus E-3 that works well as 17' x 22' show print. That's with a decade+ old 5 MP FT sensor.

Glacial Moraine taken on hike up Field Mountain to the Burgess Shale (Canadian Rocky Mountains)
Clyde Butcher hauls huge 8"x10" view cameras through Florida Everglades swamps and enlarges the plates on a 3/4 ton enlarger into beautiful wall prints.
<iframe width="560" height="315" src="//www.youtube.com/embed/LTfqyqjgc44" frameborder="0" allowfullscreen></iframe>
Most of us do want to be able to take along a variety of lenses and maybe even a second body, BUT most of us do not want to haul an "only" 65 pound bag;
And big and determined as he is; hwe still needs a loving, loyal unpaid assistant, Most of us, even if we are blessed with a loving partner, do not have a partner who will - watch the video-:
and most of are willing to make sacrifices for our photography, but not quite dedicated enough to suffer malaria a dozen times.
So we make sensible compromises. The Sony is a very interesting camera. Come to think of it (my wife is a professional musician, and I'm quite familiar with their sound equipment) the sort of triumph of miniaturization that is a hallmark of that company. However, it, too, seems to have its drawbacks. Reviews have been mixed: some have hate the (un)ergonimics. Also, given the optically-necessary-for-full-frame size of the lenses, the net saving in
system size and weight. And then there is their cost, which also becomes problematic when related to Sony's relative profusion of different mount and standards (unless one has thousands in pocket change).
For me - and I speculate for many others - the small size and weight of mFT's,
as a system in relation to the very acceptable photo quality it produces, as well as the many (affordable!) lens and body options it offers are the perfect choice, much in the same way that 35mm came to be, 50+ years ago.
--
erichK
saskatoon, canada
Photography is a small voice, at best, but sometimes one photograph, or a group of them, can lure our sense of awareness.
- W. Eugene Smith, Dec 30, 1918 to Oct 15, 1978.
http://erichk.zenfolio.com/
http://www.fototime.com/inv/7F3D846BCD301F3
underwater photos:
http://www.scubaboard.com/gallery/showgallery.php/cat/500/ppuser/5567