We have one known issue with Mavericks at this point:
Minimizing PT4 to the dock appears to cause the HUD to stop updating. Please keep PT4 up (you can put other windows on top of it, just don't actually minimize it) in order to keep the HUD updating. We are going to work to get this fixed, but that will at least give you an updating HUD in the meantime.
Should you accidentally minimize PT4 to the dock, bringing the window back up will cause the HUD to instantly refresh.
I will keep this top post updated with any known issues.