Posting this because not everyone seems to be aware of the existence of the test branch, basically a later build of the game that you have to opt in on. Its purpose is to test new builds before they become the new public build, in that way keeping public builds fairly stable. However, instability usually isn't that much of a problem for the test builds, and when people are playing online it's almost always on the dev server, that runs on the test branch.

If you would like to participate in the pre-update testing then right click on the Ground Branch listing in your library and select Properties then Beta and in the Beta Access Code area enter 'GroundBranchTesting' . You will then get an update. You will now see Ground Branch(testing) in your library.

At any time you can opt out and go back to the regular Ground Branch release.

Edit: A password is no longer needed to opt in.