Well just caught up on all the posts since last night while watching a few videos about the cameras.
First off, my prediction, from measuring the pics in Photoshop of a 56mm lens mount was was 1mm out.
It's 55mm.
I think in one vid the chap said the flange distance was 16mm if no one as mentioned it. I think someone asked on one of the previous pages.
So, as has been said, the one card slot is a huge mistake.
And to make that a format which people may not already have is compounding the mistake imho. :banghead: Some of the Nikon dual slot cameras have gone XQD and SD, and this manages the card transition for some. Looking at the battery they have used, the EN-EL15b, being put into the camera in one of the vids I'm not sure there is space for another card slot, be that XQD or SD.
Those holding out for extra slots in future models may be disappointed if the keep this battery, which seems very likely as it is a new version of the battery for this camera. Btw, you can't give Sony stick for not having two UHS-II SD slots and not call Nikon out for one slot.
There are apparently going to be four sellers (who makes the cards!) of XQD/CFExpress cards, Sony, Nikon, Delkin and the phoenix Lexar. Whether these will bring prices down is anyone's guess. The Sony v Lexar battle was starting to do this until Lexar backed out of the market. Good that Nikon say they will upgrade the camera to be able to read CFExpress, hopefully something they will do with their DSLR's.
The viewfinder and rear LCD both been getting good reviews.
The chap at B&H said he used the cameras with the adapter with a lot of F mount lenses and they worked as well as on a DSLR, and it all felt solid. He got some very nice Food shots doing it too.
These cameras are the mirrorless versions of the D750 and the D850, and are also direct rivals for the Sony a7III and the a7RIII. For me they have not matched either their own DSLR's or the Sony's in some areas. They may be good enough for a lot of enthusiasts who have been waiting for a Nikon mirrorless to start to make the change, some of whom will by it because it is Nikon regardless. For some, the wait may be seen as a disappointment and they will either stick with their DSLR's, or give up and make the move to mirrorless, more likely Sony.
For Pro's, a lot of whom use the D750 and D8**, the one card slot seems to be a deal breaker for the one off event/situation users, as it it will be for some affluent normal users. It will be hard to know if the one card slot will dent sales in a significant way, because these will sell just because they are Nikon mirrorless. If Nikon feels it didn't ,I doubt there will be a serious attempt to get two card slots into the body, which as I said, looks difficult from the video I watched.
I already have the version with the Mirror In so it does not seem to offer much because I have no interest in Video, but it is nice and shiney, is Nikon so you never know 
