I have installed both Kisantech & Doran on my K1200GT (2007). Kisantech drove me crazy and the people from Kisantech were of no help! They offered to help when I told them "The system is being shipped back to them and I need an RMA!". I have installed 2 Kisantech on my bike until I GAVE up on the kit...and the company.
As for Doran, I have it on my back the past 2 months and it works like a charm. The part I don't like it takes a bit of a long time to send its reading to the display unit. It works as it is stated, it gives an alarm when the pressure is low and when the tires heat up the pressure goes up and the alarm go away.
BMW mechanic told me the sensor can be fitted on the inside of the wheel though. I have the transmitters installed on the valve and visible but who cares, it does the job.
The installation of Kisan is a bitch with the wires extending all the way to the transmitters from under the seat. The wireless bit on Doran beats Kisantech kit.
Buy Doran with confidence, I highly recommend it.