The full list of changes is here. Visit the Plastic SCM download page to install or upgrade your Plastic SCM setup.
You can suggest and vote new features on the Plastic SCM Forum page and tell us your opinion about Plastic SCM or use the User's Voice channel, as well.
Let's move on to the meat ;-)
NewClosable wokspace tabs: This feature has been suggested by lots of users and now it's available!
Take into account that you won't be allowed to close the latest workspace. This is because a workspace at least is necessary to work with Plastic SCM GUI.
To make a closed workspace visible again, you need to open the workspaces view and make that workspace active:
BugfixesSwitching to a workspace that contained multiple opened views with a SEID condition (such as owner='me') could lead to a "Item has already been added" error. This concurrency but minor issue has been fixed.