I just got my walnut blast done by these guys yesterday. I can say now that the idle is silky smooth and the throttle response is a little better. I forgot to ask them to take before and after pics but they told me mine were pretty dirty (have ~78k miles, never been done). Anyway, the guys at AutoCouture are very friendly and very easy to work with. Will definately be doing business with them in the future.
COBB / AR Downpipes / ER FMIC + CP / AFE Stage 2 Si / Forge DVs / HKS Exhaust