I have a Predator that I bought awhile back and I would say it is somewhat useful. It's great for changing cooling fan settings, tire sizes and stuff like that but I question it's usefulness for tune programming. One feature I do like is the ability to watch engine parameters while driving. Stuff like STFT, LTFT, ignition timing, MAF, MAP etc. If you're going to leave your car pretty much stock, then I would say get one, but wait until they have a group purchase or a special.