Interesting read. Like Tom, he and I are both attorneys in our day jobs... and we have both now bounced between Sony and Nikon.
I've had similar thinking to his thinking -- which is what has led me to pre-order the A6300. It *should* work nicely with the Commlite adapter, giving me cross-compatibility. Keeping the A6300 small for wide angle uses (with the native 10-18 or Zeiss 24), and letting me adapt Nikon glass for longer shooting (Once I get the commlite adapter, I'm really looking forward to trying the Nikon 300/4 on the A6300).
But some notes -- Tom switched for size-savings, but seems to have realized that it really isn't saving much size (at least if shooting full frame with high quality lenses). You read his whole post, and you get the sense of a purely lateral move. IQ and AF are just as good as his Nikon set-up. His kit is smaller... but because he has opted for smaller slower lenses. The body is smaller, but more cramped.
I think we are now hitting a stride of equilibrium. Where there are some little differences and pros and cons, but dSLRs and Sony mirrorless cameras are essentially just lateral products. 4 years ago, when it was just APS-C NEX cameras, they were smaller, but with clearly inferior AF and inferior performance. First generation A7 cameras were clearly still rough around the edges. The Sony lens lineup was seriously lacking. The A6000 was a great leap forward for APS-C shooters, but the "slideshow" effect continued as a major drawback of EVF action shooting.
Between the A7rii and now the A6300... And with the growth of the Sony lens lineup.... Sure, there are still holes in the Sony lens lineup, and it is more expensive than a traditional dSLR. But in terms of photographic results, the holes are no longer gaping for most shooters (wildlife and pro shooters would still have big problems with the Sony lens lineup). Supposedly, with the A6300 EVF shooting 8fps without any blackout -- that's certainly better than any dSLR under $1000. For more money, the 7dii and the D500 can shoot slightly higher frame rate.
It's very hard to find objective comparisons of AF, with some people swearing that Sony AF is still inferior, while other pros claiming it is now superior.
I think we have hit the magic point where quite simply, dSLR and mirrorless are pretty close to being equals. Longer battery life on a dSLR... Focus peaking on a mirrorless. Not exactly life-changing differences.
So the question is whether mirrorless, and Sony mirrorless in particular, whether they have hit a plateau (to be either held back by technology, or held back by the lack of market demand in a shrinking camera market), or whether in the next few years, we see mirrorless fly past dSLR.
If mirrorless is to fly past dSLR, then this is the formula:
1-- Ability to drive legacy lenses with top AF quality.
2-- With no mirror blackout, the potential for SUPERIOR AF to be realized.
3-- We have some limited fully electronic shutters now. And at a minimum, we get electronic first shutters. With higher and higher resolution cameras, mirrorless cameras have the potential to make shutter-shock far less of an issue than in a mirrored dSLR.
4-- EVFs must continue to improve -- 11 frames per second with no blackout!
5-- Overall kit price -- camera and lenses -- must come down in price to match dSLR.
The A7rii and A6300 already have many of these advantages to some degree... but they are $2500 FF and $1000 APS-C cameras. Sure, you can say they are reasonably priced compared to D810/5Ds/D500/7Dii, but they aren't reasonably priced compared to D750, 6D, D5500, etc.. And the native lenses just don't have the same affordable options.
So some of those great A6300/A7rii strengths need to filter down to cheaper bodies, plus they need to cross over -- The next A7 cameras need to be able to shoot bursts without blackouts. A $1500-$1800 A7iii needs the super-advanced AF system of the A6300 and A7rii, while perhaps staying lower resolution.
Right now, money aside, I don't think I'd have any regrets if I followed Tom and switched to the A7 series. But on the other hand, especially when you factor in price, there is not yet anything compelling enough to make me switch, or to make me regret staying for now.