Just my 2 pence worth, I have a C32 that has just been serviced and re-mapped by Andy. I haven't had the pulley changed yet bit the results are epic. The car pulls like a train.
Andy has done a fantastic job for me and would highly recommend his services.
Next up the SL intake. If you do take the plunge you will not be disappointed, I have a friend with an M3 who absolutely love driving my 32.
One other thing you should be mindful of, the super charger inter cooler can leak coolant (Glycol) which can contaminate the auto gearbox. To fix is a full gearbox refurb £££. Make sure when you are looking at C32s you ask the question and good luck