Roots style superchargers will make lots of low end which is useless on fwd, but not much up top. Centrifugal make lots of top end power but not much down low. A well specced turbo is the happy medium for a small displacement motor.

The only advantage I see to superchargers are less complexity and easier to maintain. I am not a fan at all for small motors. They are not more efficient. They use power to make power. How else did you expect to drive them? Just like your accessories, they are a drag and load on the motor. The more power and more you try to spin them, the more power they take. Turbos are using spent exhaust and make the engine more efficient. Perhaps more heat, but far more efficient in the end. Superchargers are great for making what I consider medium range power (in the 200hp range) if that is all you want.

05 Mazda RX-8
06 Lotus Elise