^yea. Ill try to answer this one briefly.
there are only 2 things you have to weigh when deciding to go stage 2, and price is not the limiting factor.
You need to think:
Do I want a warranty?
-or-
I dont think Saturn even knows how to fix my car anyways...
So, if you want to keep your factory (or aftermarket) warranty, then go with stage 2. If you dont care about warranty, go aftermarket.
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Pro's & cons with Stage 2:
You dont have to know how to install a pulley, or injectors, or know how to flash your car.
You keep whats left of your factory warranty.
If you break something in the engine, you
should be covered.
OZERMAN used to get you the stage kit for pretty cheap,
www.winnersaturnparts.com, but he's out of commision
BUT,
You break something in the trans, you will get flak from the dealer/GM corp., and possibly not get the trans repaired.
You are stuck with the 3.0 pulley, and 42# injectors. (some companies make 2.8" pulleys for the GM hub)
You are stuck with the factory stage 2 tune, that runs very rich. (unless you know someone with HPT)
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Pro's & con's with Aftermarket:
You can use any size pulley that your S/C hub can fit. (anywhere from stock size to 2.5" in some cases)
You can go turbo
You can go twincharged
You can use any size injector that fits into your fuel rail, and you can tune for.
You can flash, and re-flash, and re-flash your car as many times as you want (if you purchase HPT).
You can change AFR's and timing, and a whole bunch of other parameters in the ECU (if you purchase HPT)
You can usually find a LOT of the aftermarket stuff in the 'For Sale' section, and end up getting things cheaper.
BUT,
You need to know how to install a S/C pulley, have the proper tools, and know how to install injectors.
You need to posses a basic knowledge about tuning EFI systems, and modifying the ROM's within the ECU.
If you break ANYTHING, you have to pay for it. The dealer will not fix your car if you blew the motor, and your running a 2.5" pulley on stock injectors.
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Cost:
Stage 2 (installed at most dealers, including labor): ~$1200
Aftermarket (everything brand new, w/ HPT): $900-1000