The iTSX has about 30 different gauges that can be monitored, you can only monitor one at a time on and iPhone, but about seven I think on the iPad, some I feel are foolish, but some useful, like the amount of air passing through the mass air flow. Additionally if you prefer a custom tune, which normally will produce more horsepower and torque than a "canned" tune, the iTSX allows you to save the data and send it in, and have the tune adjusted for maximum gains. One of the iTSX's greatest features as well is the performance test. It is like having a dyno built into your vehicle; it will give you a very close estimated horsepower and torque, 1-60 time, 1/4 mi time, breaking time, top speed in the 1/4, and even generate a graph of said data. The last major thing is with the iTSX is, let’s say you drive the vehicle with a custom tune, save the data and send it in while you’re still out in about. Your tuner gets updated and e-mailed to you, you are then able to receive the new tune via wifi, or cell phone data, import it, and re-flash your raptor on the spot, additionally if there is an update to your tuner software, or application, you are able to download and update it without even being home. Yes I do agree that the iTSX is slightly cost heavy, but in my honest opinion, it is well worth every cent. I hope this helps guide your choice, but I know I seem very bias, but I have never personally used the X3. So if someone could give full input of its full capabilities that might make it an easier decision.