If you're aiming at some extra power but don't want anything too serious, and you don't plan on going over 400 RWHP, then Vortech is for you. Now I'm not saying Vortech is ONLY good for 400 RWHP, but I'm just saying when you start getting into the higher numbers, another supercharger would be better. Sure, you can always get a better Vortech headunit, but other superchargers are more efficient (according to what I've read/heard.) If you plan on more than 400 RWHP, I recommend ProCharger. I'm not too sure, but isn't ProCharger better than Paxton when aiming for higher numbers? Look at Tim Matherly, he runs a ProCharger on a 2 valve and he runs consistent nines. He's also pushing around 525 RWHP and 440 RWTQ.
Off topic, I plan on going the Kenne Bell route. It takes more savings, but it's worth it for that low end torque! I know they're not made for top end power, but they can pump out some really nice numbers!