Originally posted by reh321 How large are the A9 and A7 cameras??
The main advantages of MILC are
(1) user sees what the sensor sees - after gain is applied and with lens at chosen aperture
(2) they have been able to attain "insane" burst rates
(3) focusing doesn't need to be adjust for "front" or "back"
(4) mechanically simpler
(5) seem to handle video better
Most of those aren't real advantages. The focusing is probably a real thing (although in practice my lenses were perfect out of the box). I have discussed this a myriad of times, but if you are shooting RAW you definitely do not see what the sensor sees -- what kind of color depth do you think the average EVF has? And the whole insane frame rate thing is pretty pointless for the average photographer. Once you get over 9 or 10 frames per second, you are just increasing the time necessary to pick through your photos after the fact. Who really wants to come away from their kid's soccer game with 3000 photos? I certainly don't. As far as video goes, I think it has more to do with SLR makers not investing in the codecs and things like that. When you pop up your mirror on your SLR, you basically have a mirrorless camera. There is no reason that the video on a D850 should be worse than the video on an A9, except that Sony has invested more in the video side of things than Nikon.
Regardless, at a given price point, you get very similar photos choosing between mirrorless and SLRs. The lens offerings in F Mount will far out number those in the Z Mount (without an adapter). We are talking specifically about Nikon's offering and other than have a f1 aperture lens (that's going to be really expensive) there is no particular reason I would choose it over one of Nikon's SLRs or a Sony mirrorless, if I wanted to go that direction.