These upgrades (total internal overhaul, improved electronics with increased processing power and a new memory card with increased bandwith) would seem to indicate the ability for slower slow-motion, but there is no mention of frame-rate improvements?
Since you're asking about lenses specifically, it should be noted that a full frame lens - like the Canon lenses - need to cover 4 times the area of M43, so the actually glass elements are simply much bigger. Believe it or not, but the price of the physical glass itself is far from a negligible factor. That stuff is pricey. Having said that, yes, Canon stuff is a bit overpriced.
A 10x Cinema Zoom sees fairly common use on a film set, something like an Angenieux Optimo 24–290mm or the new Canon CN-E 30-300mm. Those get strapped under helicopters, on big cranes, complicated car-rigs, where changing lenses becomes seriously impractical. Then some DP's also just want to keep their options open with a big zoom in certain circumstances, say if they are dealing with unpredictable elements like animals or working against time (dying light, limited location access etc.). Or if you need to do one of these:
Or some other zoom-specific effects.
But of course 95% of shots are going to fall into that 16-135mm range. However it's easy to think of locations that require a lot more reach - Overhead shot into a canyon, stuntmen on a cliff-face/parachuters/other extreme-sport type things. And then a truly long lens is also your friend if you want to steal shots at public spaces - yes, sounds a bit 70's, but filmmakers do still sneak their actors into real places from time to time, even on big productions (not because they can't afford the permit, but to capture the real feel of a place).
That was a total nostalgia bomb for me - there is nothing like a Jackie Chan fight scene. While a Jackie Chan movie is rarely inspired in all of it's elements (the writing often relies on overly familiar beats and the acting is inconsistent) the sheer ingenuity and exhilaration of those action sequences, wether fights or stunts, is second to none. He is simply the best there has ever been (for my money, better than his own Idol Buster Keaton).
I think Renée's takeaway from this, to simply slow down the editing, is a little too general a conclusion, sidestepping the point a bit, which is: make the audience belief the action is real by not creating it with editing (wide angle, no cuts) and by orienting the viewer within the space (same, as well as using the location).
And that's not specific to martial arts fights - take, for instance, those intense cat-and-mouse chase sequences/shoot-outs from No Country For Old Men. The Coen brothers make us feel completely the layout of the space, the plan of attack, where the people are in relation to one another, etc. with very measured camera work and modest editing. Same principle.
One thing I found fascinating in the video was Jackie's editing tip of repeating a blow to accent it, instead of the by now common practice of dropping a few frames out to speed up the moment of impact (a tip I've seen in many online tutorials, Film Riot for instance). I guess the difference is that when you have full contact fighting (like Jackie does), you don't have to "fake" your way past a slow feint.
And the american scenes singled out in the video were really illustrative of how inert Hollywood fight scenes can sometimes get. This is NOT just good advice on how to make a Jackie Chan movie, it's good advice on how to make stellar action.
That comparison leaves out the freaking 5K (!), superb display on the iMac - something that will set you back around 2000$ if you buy it separately. Come on.
That's not really how the A7r is situated - it's current iteration is far inferior video wise to the A7s, and in many ways it's photo capabilities are also inferior to the A7 mark I (slower fps, worse autofocus, the ridiculous shutter noise on the A7r...). The A7r is a specialty camera, not designed around ergonomics or well rounded capabilities - it just makes the highest fidelity photos of any full frame digital camera without any image compromises. Massive dynamic range, massive resolution, gunning for Medium Format results. I've taken portraits with it, and for that it's incredible, but dedicated videographers need not apply.