I went with Unleased tuning on my SHO, I prefer the SCT livewire and everything I can monitor with it. As for them having 2 different hp/tq figures, it you didn't go with a 3 bar map sensor too then you have the lower of the 2 as you can't run as much boost.
I'm not aware of the Edge/Fusion 2.7TT needing a 3-bar sensor? I know the SHO/MKS/Explorer 3.5TT needed the 3-bar sensor to get the most out of the tunes.