Following the uproar on the Internet about the high price of the E-M1 II, there is a lot of talk about the fact that you can get a FF camera at that price and that it will produce better image quality. This only considers the price of the camera though, when you include glass into the equation, the FF system quickly becomes more expensive than the M4/3 system. No doubt, full-frame sensors are better for noise and DR, I don’t think anybody is disputing that. But there is more to photography than technical image quality. Factors like functionality, usability, weight, in-body stabilization and availability of quality affordable lenses are all huge contributors to the end result.
Personally I’m more interested in having a compact system with high functionality and usability. The image quality of my E-M1 is more than good enough. And with the IBIS and the f/1.8 prime lenses that are affordable and usable wide-open, I very very rarely have to go above 1600 ISO and my images are quite acceptable up to 3200 ISO, even 6400 ISO if exposed well and with good PP. So I’m not willing to give up on portability just so I can occasionally shoot at 6400 ISO and get cleaner images. Same goes with Depth of Field. Yes you get better DOF control on a full-frame camera, but for my photography I find that more DOF is an advantage about 80% of the time, so again, not willing to compromise on portability and cost for razor-thin DOF. I can still get shallow DOF when I want it and I’m not really into portraits where only one eye is in focus anyway.
Again, if you don’t mind lugging 20lbs of equipment around, more power to you. I have learned that I do much more photography and I enjoy it a lot more with a compact and lightweight system, so in that sense, the M4/3 format has greatly enhanced my photography over my Nikon FF system. I do not obsess over having the best image quality available or comparing images at 200% on a computer screen. I just go out and enjoy photography.
A lot of people think that having more megapixels or better high ISO performance will improve their photography, but unless they are in a very specific niche that requires those things, most of the time it doesn’t make them better photographers, so they go on being unsatisfied and thinking, if only I had that new Canon 5Dxz GT, then I would really be making better pictures!