I have a little experience with it. I have it installed and running on a virtual machine. So far only sonos and xbmc binding started. Which works fine. Will add ZWave and rfxcom as soon as I get the time.
Learning threshold is a bit high at beginning but once you got the hang of it, it feels really smooth and you have full control. Im migrating from ver lite.

@Yveaux openHAB has binding for MQTT and it has GUI (html5 and mobile app).
https://github.com/openhab/openhab/wiki/MQTT-Binding
https://github.com/cdjackson/HABmin
https://www.youtube.com/watch?v=IlEa-R0VZ-c

Will there be a openhab binding of this?

@epierre Where can I find more info on mySensor bindings for openhab? Cant find anything on openhab.