Final Cut Pro X 10.0.6 is the most feature rich update to date
www.philiphodgetts.com/2012/10/final-cut-pro-x-10-0-6
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Theres a rebuilt and more flexible Share function; a simplified and improved Unified Import with optional list view, horizontal scopes mode (and scope for each viewer), Chapter Markers, faster freeze frames, support for new titling features inherited from Motion, more control over connection point, 5 K image support, vastly improved Compound Clip structure (both functional and for us the XML), customized metadata export in the XML (for asset management tools mostly), and two features that didnt make it to the whats new list: Range Export from Projects and a bonus for 7toX customers.