Just at the experimental stage with a local site copy, but I ran into a plugin conflict that the author would want to know about it.
I was turning off plugins to see why the Twentyfourteen Styles options would not show up under Customize... It appears to be NextCellent Gallery (the fork from NextGen 1.9.13 due to the 2.0.0 NextGen major changes) is the source of the conflict. Deactivate NextCellent, and the new Styles options show up after refresh. Reactivate, and they disappear.
I checked with older versions of original NextGen Gallery (1.9.13) and newer (2.0.59), and there was NO conflict. So it does appear to be a bug (or something) related to NextCellent fork specifically.
I plan to copy/repost at the NextCellent support page.