if i had the money i would get a supercharger... but i love the basic principles of a turbo, it makes sense.
i'm only guessing here but i would think that if you were tracking the car a lot then a supercharger would be better as it would have a 'smoother' power curve making the car more stable? But if you wanted a car that would put a grin on your face from time to time on the backroad or whatever then a turbo running high boost would tend to do that more than the supercharger..
i don't think in general terms running moderate BHP it would make too much of a difference which one you went for, although i would love a supercharger if i could afford it.. although saying that i love the basic principles of a turbo using what would be 'wasted' exhaust gasses to produce more power - it makes perfect sense!