I suppose the benefits of using a big centrifugal supercharger is the high cfm output and pregressive boost, whilst being a bit less stressful on the engine internals and drivetrain. But at the same time a big turbo would be producing a lot more power with no drag on the engine and lot more low to mid range torque.
I tuned my own car on stock internals, 300whp was @ 11/12 psi and with a 2.5" exhaust system butted to a FGK 4-1 header. The later tunes were done on the built motor by a friend of mine steve from http://maseengineering.com/
, he usually comes over 3 or 4 times a year.
Like soiled said, bigger turbo = less heat + more cfm and less boost for the same power as a smaller unit, but the trade off is more lag.
We fitted a peak boost turbo kit with a HKS gt2835r to a standard Integra DC5 engine, that made 438 bhp @ 11.5 psi, that's the same compression as a manual altezza lump 11.5:1, the cars has now covered nearly 15k of hard miles since with the only issue being a split oil cooler rad. .