And turbos are more efficient!!!!!!!!!
To further add to StuttersC excellent explanation, the opinion and trend of most modern day tuners is that superchargers are the old school way of power. The new oem trend (i.e subaru, mazdaspped, evo 8) and all the domestic guys are switching out to turbo's. I recently went to a mustang drag meet and was amazed by how many turbos where there.
Furthermore in Japan turbo has been king for many years. You cannot beat the efficiency of a modern day turbo.
Plus heat, that is commonly associated with turbos is not an issue with intercoolers.
And if you decide that you still want to supercharge, I would not go with the voretch design, as Stutters mentioned these are very inefficient and basically combine all the negative aspects of a turbo(lag) and all the negative aspects of a supercharger. Resulting in a lose-lose situation. Try doing some research on eaton superchargers(the ones jackson racing uses) they are much better.