Fixes in this SteamVR build include an issue that could cause a system hang and an issue where the image would appear to shift around.
But perhaps most exciting is this SteamVR update is supposed to improve the SteamVR performance on AMD hardware. Additionally, there is improved apparent latency when a VR application is running.
More details at SteamCommunity.com. Can't wait to try out the beta this weekend! My initial SteamVR Linux thoughts were detailed last month in Trying The SteamVR Beta On Linux Feels More Like An Early Alpha and SteamVR On Linux Currently Runs Well On At Least A GeForce GTX 1070/1080.