Thom Hogan has many viewpoints, and I don't always agree with him, but he presents some sensible thoughts in this article about mirrorless cameras. Well worth reading.
The Good News, Bad News Mirrorless Problem | Sans Mirror — mirrorless, interchangeable lens cameras | Thom Hogan
Frankly, while I have no opinion regarding the author one way or the other, in this specific case, I tend to agree with him just based on this considered POV.
All of my Mirror-less (with EVF) experiences have been a mixed bag.
I think it is really cool that you can adapt so many optics to the Sony mirror-less cameras, but that is a side novelty for a lot of photography I do for both pay and pleasure. Nothing really new, I also adapted quite a few favored lenses to Canon EOS DSLRs in past: Leica R, Contax C/Y, AF Contax N.
While small is cool, it amazes me that reduction didn't lead to simplicity and elegance. In Sony's case the camera's have become incredibly complex sporting a dog's breakfast menu. With the A7R they provided a massive FF meg count, then massaged the RAW file poorly, and put a shutter in it that rivals a MF mirror flap to further negate the massive meg count. :wtf:
The faster prime lenses everyone wants/needs have been slow coming and turn out to be gigantic. As they have added some features like IBIS, the A7 cameras are getting bigger. I do not know how the later A cameras work, but the lag of the A7R is a real drag ... Decisive Moment photography requires shooting before the moment even happens.
For me, the bloom is off the rose with Mirror-less. If I had the time and resources to dedicate myself to yet another gear debacle, I'd just get a D810 and a few nice primes.
- Marc