George,
I think you are incorrect about the DME. I am pretty sure that the RS, USA Cup and Carrera Cup use a different DME than the USA Carrera 2 which yields slighly more power.
As for the engine itself I agree there is alot of folklore about this and I agree it's possible that a regular Carrera 2 engine is just as good. Some take your position but others say the factory definately used a selected engine in the RS models including the USA Cup and the Carrera Cup cars. We may never know but I like to think these engines are at least on the right side of the bell curve.
Further, the Carrera RS has the blower motor. Only the Cup car has the bypass tube. Little details, but we all love them.
