Like Michael, I have a D-800 system with a range of lenses, and an m4/3 (Panasonic) system with a range of lenses; and for the same reasons. When I'm working out of my SUV, I take the Big Trombone, and a suitcase full of lenses. Why not? Otherwise, it's the m4/3. But as for the future of the systems, I somewhat disagree with the article. As he says, the A7 cameras are in fact the size of some m4/3 cameras -- almost identical in size to the Panasonic GH3. But the GH3 is the largest of the m4/3 cameras, because it's basically a movie camera, and has to meet some movie camera requirements. I had one for a while, because I liked the sensor, but it was too big; not enough difference between it and APS-C cameras, so my son now has it. The future of the m4/3 still-camera systems, I believe, lies in the smaller bodies like the GX7, which are notably smaller than the A7 cameras (or the GH3.) I'd agree that small lenses are coming for the A7, and why not, if Leica can do it? But the thing is, I don't believe people really want those small Leica-style lenses...because the small lenses that are coming aren't zooms, just as the small Leica lenses aren't zooms. And I think people really want zooms -- and the enthusiasts want fast zooms. When I'm traveling by air, as I did this morning between LA and Santa Fe, I take my m4/3 system in two small padded Eagle Creek cases, not specifically meant for cameras, and I carry them in a business-style backpack. My basic kit includes 2 f2.8 zooms, (12-35 and 35-100) plus an f4 7-14, an Olympus 45mm and the Voightlander f0.95 42.5mm, a battery charger, and two spare batteries. Sometimes, I'll drop an extra GX7 body in the bag. Not bad, for a system that shares a fairly small pack with a Surface tablet, pens, pencils, books, chargers, spare glasses, sun glasses, pills, etc. That system is *smaller* that two of my Nikon f2.8 zooms alone. In my opinion, in a situation where cost is not a major factor, the *only* real reason for carrying a system smaller than FF is size and convenience..I'd never argue that the image quality is as good, or that the systems are more photographically flexible. But if you're going to go small, I would suggest that you want to go as small as you can, and still meet your IQ requirements, whatever they may be. The m4/3, for me, meets my IQ requirements for the kind of shooting I use it for -- otherwise, it's the Big Trombone.
I should also mention the epitaph I plan to have inscribed on my tombstone, which I feel is relevant here: "No great photograph ever depended on resolution."