The latest Steam Beta client is not recommended to impulse buyers, as it allows for remote downloads, making it even easier to lose your rent money. To allow the update, access your account details, hit the Change button, and allow Steam Beta Update. You know this, probably.
Your home computer will need to be on and running Steam before it’ll work. To make use of it, access your game library via the Steam website whenever you’re out and about. Simply set games in your library to download, and your computer at home will do the rest.
Outside of this, the new Steam client reduces excessive system memory usage while downloading updates and adds debug code to diagnose issues.