I used Multiplicity for a few months but switched to KaVoom KM. I had a problem with Multiplicity placing the mouse cursor at screen's edge even though I used a hotkey to switch monitors. KaVoom does a better job for me of leaving the mouse cursor where it was when I made the switch. That is a very minor complaint and I didn't do much research to solve the problem. Both programs work quite well with mouse look and Hotkeynet. I currently use Hotkeynet to control my main on one monitor and two alts on a second. I use KaVoom KM to toggle back and forth.