turbo has the advantage of being able to easily up the boost and intercool the intake charge. jrsc raise the intake temps the more you spin it (up the boost) with different pulley combinations. the hp/lb of boost decreases as the intake charge increases.

jrsc cars are fun, but for the time, effort, and ability to use a fmic to cool the charge makes turbo a better alternative. you could go with a vortech with the aftercooler if you had to have a sc, but it's just a turbo on a stick.