I am debating whether to get either a Spoon header, hytech, or SMSP.. How much more power is the hytech or SMSP going to yield over the Spoon 4-2-1?

 

Depends how extensively you mod your car. The SMSP and Hytech headers will perform better when there are more mods that allow them to perform at maximum potentional.

 

Closing this as its going to turn into a flame war. Along with a bunch of Do a search posts.

IMO
Spoon - good choice for Stock to Mild applications
Toda - Good for apps with larger cams IE B's C's Jun 3's etc.
HyTech and SMS - you'll notice more on a highly modded engine than on stock, Both are good pieces.