Disclaimer - I am in no way professional photographer (about 5-10% of my photo sessions are being paid for) and I am quite happy 6D owner (despite its shortcomings). I had about an hour to play with the 6D2 just today, but since it was a preproduction piece, I was not allowed to take any raw files back home nor did I receive any definitive information about sensor (and I did asked rather persistently). So take all following informations as a subjective opinion of a single amateur photographer. This is not a review, rather preview/impression/brief hands-on thing.
Handling and build quality:
No suprises there. It's very similar to 6D, although "Magnify" button is where I'm used to press "Q" and felt a little too spongy (other buttons felt just right). I was right at home, being used to my 6D for almost four years. So for those, who upgrade from 60D, 70D, 80D or 6D, there is (almost) no learning curve and they should be comfortable using this camera. Ergonomics are on spot (as used with Canon), no complaints there. Whole construction is solid, nothing twisting, bending or squeaking whatsoever.
AF system and viewfinder:
This is a huge step up (obviously) from the original 6D. There was 5D4 as well to compare to and while there is a difference in AF pattern, it's actually rather small. Basicly add another column on both sides and you have 5D4 (but horizontal points only AFAIK, crosstype points are about the same). But all in all, no suprises here. Intelligent viewfinder as we know from previous models with two-axis level, 4x5 grid, AF points and what was a bit of suprise to me was white status bar numbers instead of green.
DPAF and LiveView:
Oh my god, that DPAF in conjuction with touch screen is simply amazeballs. Canon hit a jackpot on this feature. Combination of fully articulating display with very good touch capability (fast and precise, I felt like I was using my iPhone, very responsive) and incredibly fast DPAF is simply pure gold. This is a feature I could get used to very quickly even on a fixed screen (like 5D4 has). I had a Fuji XPro2 + 35/2 WR lense for a weekend rental but DPAF feels actually faster. So this is truly viable option for current and future MILC from Canon, when they finally decide to commit.
Personal note: VariAngle screen feels like a locus minoris resistentiae to me, I'd prefer simple up/down tilt screen on a metal frame, much like Fuji or Sony have. But this is I guess rather subjective and very user based issue.
Touch interface:
Anyone, who can use a smartphone can use this camera using touch interface. It's really very responsive and being first-time user, I still had no misclicks. It just works - period. But I'm still used to wheels and dials, so touch interface wasn't faster. But it's a nice feature and definitely very desirable feature. Thumbs up from me.
Image Quality:
Sorry. As I stated earlier, no photos taken home were allowed and I really won't judge anything by the 3" screen displaying JPEG previews.
I won't repeat technical specifications as they have been repeater over and over ad nauseam. If you have any additional questions, I'm happy to answer them.
Will I be buying this camera? I guess not. At least not now. My 6D works just fine, I'm happy with its output and I'm quite used to it by now. So I guess I'll just patiently read upcoming reviews, wait for some cashback, rebate, sale or promo to sway me over. As of now, I'm happy 6D camper.