I have the SB on my other car and LOVE it. Yes, it does NOT give you any more HP, but who cares. It completely changes the throttle map and DOES make downshifts so much quicker when you get on the gas.
It's not always about getting more power. Sometimes, its about how easily/seamlessly you can get the power down and the SB does exactly what it promises (at least on my car). It is on my list for the T4R as well, over the winter...