I'm using Ubuntu Mate on desktop, and multi monitor is wonky. After each reboot I have to pluck out and put in cable for the bigger main screen so it can be detected by system. Then have to re-arrange position of monitors on the desktop. Might be an Nvidia issue tho. Still better than Windows.
Here's your problem. Going for something slightly more offbeat and less supported is going to produce problems. Last time I looked it was still running on X, so it's never going to be a great experience.
