I've got a basic manual one on my Fazer and an auto one on my Multi. Both are very good once you've routed them well enough. Just have to remember to turn the manual one off when you stop. They've got a 3D printer now and last I heard they were experimenting with a sold (printed) final delivery system.
I had the basic one on my GSXR 750 K4. Lasted a week then nozzle ate itself. Principle fine but for the price you get what you pay for!! I think it also matters what type of bike you fit it too. On their web site were lots of happy punters but I didn't get on with it. E Scotoiler on my Mutley not much better either. See chain thread.