Primarily a bug-fix release. Still got a few highly requested features (“distribute removed weight to other influences”, several fixes to mirroring process) - did not want to delay the release further as we had some pretty severe Maya 2017 related issues.
Single installation supports all installed Mayas, thanks to the new way Maya discovers it's plugins.
For each platform, there are two downloads - installer and a plain .zip archive. Use installer for automatic setup, or .zip if you need more control over the installation.