The version that ships with Rhino6 is almost entirely the same as the last release for Rhino5. There are no new features, though there may be some new components… I lost track. GH1 for Rhino6 does contain many bug fixes that we’ve accumulated since the last independent release.
One major thing I’m still working on is the ability to scale up (parts of) the interface so the icons and text aren’t too small to parse on small-pixel screens.