>>2569233>>2569229I've owned and used these cameras extensively, and also borrowed and used the 16mp variants. I have no experimented with the new EM5 II with the high res mode.
Even using a tripod, using a Cambridge calculator to determine the smallest aperture possible before diffraction affects the image, and even a long self timer for maximum possible resolution, I find that the images are worse in resolution than any old hand-held shot from a full frame camera such as a 5D III, which I've borrowed from stores for experimenting. And that applies to the EM5 and EM10 as well. I haven't seen how the GH4 does.
I am primarily a 4/3 user, and I think it's a great system, but IQ is not what you buy a 4/3 type camera for.
If I was not very interested in size, weight, usability, speed, functionality, /price/, etc., I would definitely prefer to use something like a sony FF slt with the EVF and full time live view. Or a 645Z if I was serious about maximum IQ.
Some of the glass for 4/3 is very expensive, in the $1000 class, but in the same vein you can say that some FF SLR glass gets into the $4000 class, coincidentally quadruple. You do not have to spend any more than $300 for any given lens in the system, and that's part of why I like it so much. They're all very small, and very cheap, and there are almost no 'dud' lenses in the lineup that perform disappointing. All I can think up off the top of my head, was that very first old 17mm f/2.8., and the /slightly/ slow focusing 20mm 1.7. Sine then it's been sunshine and daisies, on the wallet, on the shoulders, and the results make me plenty happy.