I can answer a few of the questions from what we've done.
The DASC runs 8PSI. From memory it ran a piggy back system for the added fuels and produces roughly 60% more power.
Did we feel the difference? Hell yeah, but we were much happier with the rotrex setup
BTW, I would not recommend either one of these systems in an E46 318i running fly by wire and valvtronic.