I don't have specific experience for comparison on the facelift E53 but in general the Stage 1 tunes of any variety don't give you more power but an overall more enjoyable driving experience. Such has been with the APR software I've experience on VAGs and various packages on the JDM vehicles I've run. As for Dinan, they make some all around excellent stuff, for $200 you will wonder why you didn't do it sooner.

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Again Daily Driven SC'd 4.6iS, whats the point of having a sweet ride if you dont use it all the time.