Steve, one thing is that the RB motors may not have as much peak torque, but they sure have it a lot earlier then the SR20.
It is because of this they will come on boost earlier compared to teh SR20. Everything is a rapid succession after each other. Just like a well designed FMIC will bring on boost earlier due to the denser intake temp, providing better combustion, faster meaning more power earlier.
I think a lot of people fail to realise that and with this day and age of budget kits like the Hybrid IC kits, more and more people will not realise this.
What sort of Grunt are you making?