The SCT xcal 2 is a great tuner. It is tricky to figure out how to datalog with, but once you do, is worth its weight in gold. As there are no local tuners in my area, I have used mine for everything from minor changes, such as gears and tire size, to major changes, such as an entire tune once I finished the procharger install. A handheld tuner is a must for anyone doing any kind of mod to their mustang. The price may sound steep but has saved me thousands in the long run. Highly recommended!!
But......sometimes when using the tuner it can blow a fuse (fuse 6)....so just in case this happens to you now you know what fuse to look for.