Ok to be able to use the new Beta UI if you would like too. Follow these steps.
Download the Unsupported 8.20 Build.
This has new .dll version's needed to run it and more.
Create a new Vista Bottle once installed.
Install Steam to it and update to the new UI Beta from steam.
It may look like it has frozen once it get's to the User Login Screen, but please give it some time it will run.
If it doesn't run or crashes, go to the Wine CFG for the Vista Bottle and change Steam.exe to Vista or Windows 7 and try it again.
If still not luck please report here so we may help.