The Mir team is calling for a round of testing for Mir and multi-monitor support specifically starting today through August 28th. Help us during this round of testing to make sure Mir and features are thoroughly tested on as many devices as possible.
You can find all the details you need on this wiki page. The tests will use the ppa:mir-team/system-compositor-testing ppa. Full instructions can be found on the wiki page.
Please report your results good or bad on the provided wiki results page or the package tracker.
Thanks for helping make ubuntu better!