Porsche brembo caliper brake swap for 473$

Any "before" data? How much improvement?

No unfortunately. Not exactly a fair comparison because of the weight but I found a test on yt with a RC Dakota equipped with 11 inch single piston caliper front, 10 inch drum rear brakes have a 3 run avg of 168.33 feet.

Weight difference is substantial though. Around 3100 lbs for my Duster, while the Dakota comes in around 4000 lbs.

The same guy with the Dakota proceeded to swap to viper 13 inch rotor/4 piston brembos front and rear with better tires and had a 5 run avg 103.4ft.