I replaced my F650GS cockpit by an IMO 100 this spring. It took me more than a day to fit, mainly because I couldn't find a replacement plug for the original cockpit plug.
Once installed correctly, it's been working
fine ever since. Only, from time to time I get
a strange speed spike (like 200km/h), that
lasts a second or so. It doesn't seem to
influence the unit, nor the calculations.
I haven't figured out why this occurs. It is rare though.
It's been quite useful in giving me the day's statistics, such as fuel consumption, average speed and such. It seems to be well built and rugged, and have still to find out how long it'll last until it breaks.
You should have some electrical knowledge before you attempt to install this unit. Though there are instructions, in places it is rather vague and assumes enough knowledge about electronics.
When I installed the IMO, I also replaced the control lights, and this where I had most installation trouble. Installing the IMO only should be easy, as there are two wires for power (+ and ground), a connector for the wheel sensor (supplied), a wire for the RPM signal (you need to be careful here, or you can fry the unit. the instructions tell you what to do) and a connector for the remote control (supplied). Mine also had a connection for an oil temperature sensor.