I see no reason to use any setting other than 9, don't have to use the extra power. Right foot mostly under control: but hell, it shocked my passengers, and I suspect others, when I needed to use it!
Thank you for the chat on Friday. Transferred the unit to my new 335d. Using setting 6 the effect was immediate and obvious. Previous slight "hesitation" when pulling away now gone completely, car is much more responsive, the auto box seems to use lower revs, car is quieter and smoother, economy improved etc. Quite how the same unit can perform so well on 2 different cars is a mystery to me (though perhaps not to you guys!) but it does and I am again, deeply impressed with the product. A brilliant car just got a whole lot better.