Theres alot of opinions and most are great! Its time for brakes. But I don't think slapping a set of DP race pads is going to do much. Do I go as far as a Brembo swap, with stainless line, and an oversized rotor and DP pads?
For as much braking as the 300's do, SS line and pads are a great start. But the rotors are also fairly cheap and a good upgrade. Master cylinders are nice for feel, but the stock master works well enough if you want to save some cash.