I personally, wouldnt bother with a remap - and all the hassle that goes with it. It you want a faster car - go out and buy one and be insured and warranted properly.
My point with the insurance is that for me it would be cheaper to insure a 335d than a remapped 330d. And both would have roughly the same power.
BTW, what is the most miles have you had out of a tank?