Brake, cable and pad all make a difference to stopping power, although standard Shimano pads are generally awful in the wet compared to their dry performance (having said that, DA 7900s are supposed to be better now).
Modern dual-pivot brake(s) is the most important thing (assuming you need caliper type brakes) - after that, Swissstop green FTW in the wet. Kool Stop salmons on a budget.
Brake, cable and pad all make a difference to stopping power, although standard Shimano pads are generally awful in the wet compared to their dry performance (having said that, DA 7900s are supposed to be better now).
Modern dual-pivot brake(s) is the most important thing (assuming you need caliper type brakes) - after that, Swissstop green FTW in the wet. Kool Stop salmons on a budget.