Vortech vs Stillen Stage II

I want to get a supercharger for my 2003 g35 coupe and i dont know which one to get. If anyone has an opinion of which supercharger is better the vortech or the stillen stage 2 please let me know. or if there is a different one that is better? but know turbos please im looking for a supercharger.

Any opinion would be great.

Thanks Rob