Certainly, the pads on standard R56 S brakes might as well be made of cheese. The R53 JCW pads are a lot better, but you can get better.
To the OP, stick some EBC yellow's, or Mintex 1144's in at the same time as new fluid, and see what you think - it'll cost you under £100 for the parts, which is a lot cheaper than the JCW Brembo's.
It's the pads that make the biggest difference to brakes