SCT is a budget tuner with problems. They can't make it work right with 2 and 3 bar maps. It's pretty much stuck in the mud. Think about the facts, if your using any tuner device that works through the already known limitations of the factory pcm and poor quality O2 sensors, you have to constantly pay someone to guess an updated flash for you just like B&G did for years.
Even if you fit the pcm criteria to have them sell you software, your bulding from scratch and still under limitations of factory O2's. The factory pcm's are already blowing up do to the amount of tuning updates they were not built to take. SCT leave's alot on the table. Unlike the FAST XFI or even Accel DFI that come with wideband and complete control.