Depends what kind of races you participate in though. For courses with lots of straights and high speed sectors it's nice to have a turbo because you get lots of power as long as you keep your revs up. For tight courses with high-speed and low-speed sectors it's not as good because once your revs drop you get all this turbo lag, especially if you have a huge turbo.
Of course, from a pure performance standpoint turbos do give more than superchargers. I still wouldn't mind either one. Any boost = win.