My concern about Ravelco plugs is that if someone cuts a CAN wire, the vehicle can have expensive electrical issues. Especially with so many systems that are by wire these days, such as newer F-150s (where the accelerator physically does nothing other than tell the computer what to do.) . I have seen some very crappy wiring jobs and a Mercedes Sprinter pretty much ruined by a botched alarm install, so I am wary about things like that.
However, if it works, it works. There is a range of Ford trucks that really need additional ignition/ECM security, and if the Ravelco install does the job, it almost is a must have. Just make sure to have extra plugs on hand.