Some recent updates may include beta builds, you could also notice the new launch option when trying to run the game from Steam shortcut.
What do these beta builds do? They're intended to safely check some new features or capabilities before making them available for everyone. So if your game is unstable or running slow, or if you just want to try some untested feature, use beta option in your launch menu.
In this particular update you can try build 927 beta that is more smooth and could be more stable than ordinary 927. If it's not, please let us know in the comments.