I've had great experince with both companies, great customer service from Bluefin and an easy way of DIY remapping, go to the HQ in Bucks and they will give you a 15% discount and before and after RR - £509 inc.
For the S3 I went with GIAC and its a superb map, very smooth with all the functions and then some of the Bluefin application, slightly more expensive but worth it IMO.
Have a read and make your decision from there, others to consider are Revo & APR both switchable and similar pricing.