first, it helps to understand how both work. both do the same thing, which is cram as much air in to the intake manifold as possible. more air=better combustion=more power. the difference is in how they work.a supercharger runs on a belt drive, just like your alternator, water pump, ac, whatever. it uses power from the engine to spin its turbine and cram air. very effective, and always providing power, but it takes power from the engine to run, so the overall gain is slightly lower, and your mileage will likely suffer a very small amount, since aspirating a gas engine doesnt necessarily increase efficiency.a turbo charger uses the pressure from the engine exhaust to power its turbine. it takes no power away from the engine to run. the drawback is that the power increase is only substantial at higher rpm's, since that is when exhaust pressure is greatest. the delay before the turbo kicks in is what people call turbo lag. its not actually a loss of power, its just the engine running at stock power before the turbo spools up. at its peak, a turbo produces more power than a supercharger, but a supercharger boosts power throughout the rpm range, instead of just in the power band.as for installation, usually a supercharger is easier to install, since you dont have to modify the exhaust system, only the intake. under normal usage, there really isnt any difference in the durability of either, but in racing and extreme tuning applications, a turbo will fail first because of high exhaust temps burning up the internal components.for a normal driver, a turbo is usually better, since it requires less regular maintenance, and the peak power is higher, along with the awesome turbo sound.for a racing application, it really depends on your driving style, car setup, skill level, and how much you plan on tweaking things later. superchargers are more forgiving as far as abuse and over-tuning, but again, turbos provide better peak power.