I have heard that the throttle sensitivity booster is a good mod. To give an example of an issue my G56 manual transmission truck has is that the RPM's "hang" on every shift of the truck, just like having your foot on the throttle when pushing in the clutch when in fact you don't. I have read many others with manuals complaining of this issue as well so it's a well known issue. I must admit that I haven't done the mod yet though, mostly because I am worried about the possible warranty issues. One possible benefit I have thought about with this condition, however is that it may be helping keep turbo boost up between shifts which is definitely a good thing :B