I would think that the calipers wouldn't make a huge difference. Maybe going from really low end to lets say Ultegra or SRAM Rival might actuate more smoothly but I would think if you are doing huge descents heat on your pads might be making them mushy. Soft pads grab great but when they heat up they are less effective because they are melting. I haven't riden Ultegra but I can vouch fro SRAM Rival. I have tons of stopping power.