rotary>piston

It is definitely true that an SC set-up is not the cheapest or best set-up for a fast FC, but is unique and has it's own advantages for street use.
Here's my Experience:
I own a 91 MR2 Turbo (11 psi, which is stock boost), and I recently got to drive my friend's 89 MR2 SC running 12-13psi.
His car had a VERY flat power curve. It felt the same from 2000rpm to 6500rpm. I think those cars have centrifugal chargers, but it sure didn't feel like one. Anyway, it's a lot of fun because there is always a decent amount of power on tap. Around town it's much better than my car because you can pull very well even a 2k rpm.
My car on the other hand, has very low power at 2k rpm. So driving around town (2k-3krpm) can suck because there isn't much power there. My car is a lot faster and pulls a whole lot harder, but that is only when the turbo is going. So yes, my engine is much better at making power and my car is faster, but his car is better in town. If you want to go SC I say do it. It's really cool to drive and it's unique.

Your choice is basically: Turbo-lots of power, faster, but not always ready to go. Supercharger-power on demand all the time, less overall power though, and you don't get that cool turbo hiss.