aly324

While it's ultimately a matter of definition as you say, it seems to me rather more natural to consider the speed booster + lens a new lens with a new focal length, than to consider the speed booster part of the sensor. Same as a wide angle front adapter or a teleconverter.
 

Step back and take a breath.
Canon product development aren't stupid. Neither are they at Nikon. And Nikon is barely at the hybrid video/stills party.
So what's at play?
Pure business strategy.
You touched on it.
Camera companies could care less what Andrew Reid or I have on a wishlist.
Why bother compete with Sony/Panasonic?
We sometimes forget that Japanese manufacturing operates as a giant consortium, with players 'accommodating' each other in support of the bigger picture.

Yes. Any extended use in warm weather (actually, doesn't even have to be that hot) will cause it to overheat when shooting 4k video. The battery grip "fix" isn't really a thing. Some report it as helping, but I doubt the accuracy of their findings. It's never fixed any of my Sonys that overheat. (Even my A7SII on the latest firmware will overheat when shooting in direct sun, and that's with a grip.)
I shot with an A99II for several months. Loved it. But the overheating was becoming more of an issue as we're heading into the summer months. (Worked great in Norway though!) Tip: the A99II (and actually all new Sony cameras) can use the dual-channel wireless receiver on the hot shoe.

I've used a number of Leica M, R, and S bodies and lenses. Now I shoot stills with an S 007, and videos with a Sony FS7 and A7Sii. I would love for the next S to be upgraded for video. (Someone above mentioned an upcoming one, but that's really based on one poorly translated sentence from an interview with Leica CEO and I think not reliable.) Before that I'm also considering an SL as sort of a combination of the S and the A7S ii. It'd be nice to be able to carry one body instead of two. But after using the S, I don't think the SL's photo quality will suffice for me.
In my mind there's little doubt that Leica gear is overpriced (especially when bought at retail prices) relative to performance. At the same time, the merits and aesthetic qualities of Leica glass + processing cannot be fully captured by DXOmark and other quantitative metrics that naysayers tend to cite. For me the richness and subtlety of the colors are always what strike me. Zeiss glass is sharp, Canon and Nikon glass are sharp, but the colors aren't the same. Increasing the saturation or vibrancy in post doesn't yield the same results.
This is definitely subjective, and much harder to pin down than "sharpness" and even bokeh. But the difference is there in the images, and becomes very noticeable if you use the equipment over a long period. I don't think it's about irrational love for a brand or Leica mythology at all.