I've got the SF3/X3 Power Flash Tuner and have been really happy with it. I purchased it from Steeda as a package deal with the Steeda Cool-air intake. The nice thing is that I can get tunes from more than one source, and i'm not stuck with one supplier if I decide I wanted a Bama tune, I can go get one, or one from Steeda, etc... Lots of options and it's really easy to flash the computer with a new tune.
In my opinion, this is not something you want to every go cheap on, because if it's not right, the fallout could potentially be very expensive. Just my 2 cents.
2011 Grabber Blue GT California Special, 3.73 Gears, 6-Speed Manual, Steeda CAI, Steeda 93 tune, aluminum driveshaft (The Driveshaft Shop Co.), MGW shifter, Roush axle-back exhaust, Roush Side Rocker Panel Splitters, Ford Racing BOSS 302 front splitter, sound-tube delete, painted plug covers, JLT oil separator. Shelby transmission scoop & powder-coated trunk brace & many more items...