Proton/wine are no longer required, driver is now loading lens distortion using https://delta.rocks/blog/lach-stuff/champagne, you no longer have to deal with lens distortion helper startup failures/set any env vars, etc
Driver is now standalone, meaning it is now compatible with other headsets, doesn't need to override files in SteamVR distribution, and is no longer required to be reinstalled every SteamVR update
ViveHid status stream was reverse-engineered, SteamVR now can react to volume and microphone toggle buttons, to IPD changes, and to system button (on the left side of headset) clicks