The all new interface and runs as sweet as a nut and using OSX 10.12.1 Sierra on my two iMacs.
NOTE : In a dual monitor setup your Photos/Audio and Titles/Generators have moved position from above the timeline/VU meters to this new position, this is not explained in the link below.
Another annoying feature is by default your VU meters are absent so you need to click on the wee meters beside the timecode to activate the far more useful bigger VU meters.
For a quick overview of the new components visit this web site (Note : Single monitor setups).
Look at the new MacBook Pro and how easy now integrates with FCPX.