Funny, I just finished tracking and sending a client the comps when I saw the announcement that 10.3 has been released. Here is the press release (covering the new GarageBand 2.2 of iOS as well because the two apps work together over iCloud)

http://www.apple.com/newsroom/2017/01/garageband-and-logic-pro-x-music-apps-get-major-updates.html

What’s new? Touch Bar support, Alchemy on iOS GarageBand, “users can upload a special GarageBand-compatible version of a Logic project to iCloud, which they can then open on their iOS devices and add new recordings whenever inspiration strikes. When the project is saved back to iCloud, any newly added tracks will automatically appear in the original Logic project the next time it’s opened on a Mac”, and more.

Here are the full release notes for Logic Pro 10.3

https://support.apple.com/en-us/HT203718

Have fun, and don’t forget to backup first!