A good experiment. How much brighter is the new led vs the stock one? Maybe a 'throw' test by going out at night and shining on reflectors/cars parked on the street. How far away can you see reflections? Remember to hold the light next to your eyes for the retroreflective effect to work.
I too have noticed that there isn't a big difference when swapping a Nichia CS into somethign that overdrived another led. The dorcy1aaa looks like a Nichia stock, I put a CS and it's only slightly brighter (not 2x) to the other one I have.