I'll do my best to spread this information over to the Performance thread as well, but it seems that all the questions are over here.

The difference between the SB and tune are night and day. The tune remaps your fuel and ignition tables. Leaning out the ration and advancing the timing ever so slightly. Very similar to the old days of tuning a carb and distributor. Good thing about it is it is an increase in HP and TQ, not as much as normally advertised as the tune is set up for the MB motors and they have larger injectors, but usually around the 20HP mark. The SB targets just the throttle response. It will make you accelerate faster due to the instant apply of WOT. You will not gain any HP from this mod, it just seems that way.

As for the differences in the two tunes. With an unmodified Crossfire the tunes are going to be realtively the same. We make ours a little more conservative to address the smaller injectors. With mods such as a CAI or any induction mod you will need a very specific tune. With our stage 1, the tune is completely different to take into account the large injectors needed for more HP.

Hope this helps those in question.