I picked up a Sprint Booster version II with the Mode button off ebay for $150. This thing makes the car feel the way it should of came from the factory. It does take the lag out and if you have a steptronic the tranny downshifts alot easier to pass. Well worth the money.
My Build Thread - S54 Vanos Info Thread
-TTFS Engine/SMG Tune- Evolve Eventuri- SGT Headers/Sect 1 & SCZA-
-UltraGauge -Orion V4's- CF Lip/Diffuser- LED Fogs- Valentine One- Turner 12.5/15 Spacers-