Back2You is not cheap to buy, but it works well and seems to be cheap to run. I bought the version with a giffgaff SIM pre-installed, which arrived with everything it needed to get it up and running. Activating the SIM, linking it to my phone and setting up the tracking I wanted was very simple, as is watching the tracker through the web connection. Fitted to the bike, it looks like a slightly bulky motion-activated light. It would be hard to tell without looking more closely that it was a GPS enabled device. I have currently set it up to trigger when it moves at over 45kph, which happens fairly regularly as it's on my son's bike and my wife gives him a lift part-way to school. It records these diligently, and also lets me know when the battery is running low, which happens about once every 3 weeks. Overall, it does exactly what it promises to do, and gives me confidence that we would be able to recover a bike if it were stolen.