Congrats Guy!
I am sure many will gradually find this replacing their current DSLRs. I know I have already. Will know how it performs in the field in two weeks
Sure, the speed is already amazing but there is a lot more going for it.
For me what is already impressive is the sheer amount of customization that is possible with this camera. There are four custom buttons that are programmable, three custom shooting settings that can be stored in camera and an additional four that can be saved on a card. All can be transferred to another camera by copying to an SD card. Then there are three pages with a total of 18 menu items that can be stored in 'my favorites' section like on Canon. To top it all, the key settings can now be set via two dials on top left, so you can change frame rate instantly, the bracketing, self timer, Auto vs manual focus etc. The custom shooting settings can be recalled as sticky or if you assign them to a custom button you can have the aperture/shutter/ISO/Focus all instantly change for a particular shot while pressing a C button and then going back to your regular settings once you release it.
On my Canon 1DXii this was possible too, but you could only change to one set of parameters and to alter those was a pain. So why is this useful? Imagine you are shooting an animal running, you take your usual shot to freeze the motion, then you instantly press C1 and take the shot while panning the camera and you instantly get a motion blur. Works amazingly well for a flock of birds too.
Just did some testing last night with the buffer and various cards. Interesting stuff. You can store the same or different images on the two cards (i.e. RAW or jpg) in various combinations. However, it only writes at UHS-1 speed to slot 2 even if you have a higher speed card in it. Wish they had allowed both slots to be equally fast at writing.
What is interesting is that jpg files seem to write much slower than RAW. So even if you have a superfast Lexar 2000X card, jpg are not much faster in either slot, at around 50 MB/s (fine quality). RAW files OTOH do benefit from a faster card. I measured the Lexar 2000x to write at 190MB/s while the Sandisk 95MB/s UHS-1 card manages respectably at 89 MB/s. Not bad for a card that costs almost four times less.
The buffer is giving me around 230-240 RAW images before it begins to go single shot. I am getting over 400 images in the buffer with the jpg setting.
In the 'Sort' mode where you write RAW to slot 1 and jpg to slot 2, it is still amazing. I am able to get around 230 files in the buffer before it becomes single shot and of course the time to write to both cards gets longer though not by a whole lot.
So here is the rough summary on the buffer and time to write to the card(s):
RAW images: 230 to 240
Jpg images: 440-460
Time to clear buffer (depends upon the card):
RAW: 30 seconds with Lexar 2000X UHS-II card, 68 seconds with Sandisk 95Mb/s UHS-1 Extreme Pro card.
Jpg: 65 seconds regardless of speed of card
Dual mode:
Both RAW: 75 seconds, slot 2 card does not matter
Slot 1 RAW, slot 2 jpg: 44 seconds with Lexar 2000X i slot 1 - slot 2 card does not matter.
I did not test jpg in both slots.
what is also interesting is that the battery life is amazing, I must have shot off 7000 images in the above tests, battery was still at 72%. Of course there was no focus tracking or chimping during this process, simply setting the camera down and shooting away.