I recently had to replace my rotors. The original equipment was Ultegra, but I always thought that the black interiors of the DA's were jsut cooler looking. According to the literature, they are slightly lighting and the black brake fins disperse heat better. That may be the case, but I can't say that I really saw a performance difference. But the DA upgrade was only a few bucks more, and they do really improve the look in my opinion. Usually, I would opt for performance over looks or cost, but in this case I'll probably always stick with the DA's.
I installed these on my Trek Domane carbon and they look awesome! However, they squeal, bad!! Imagine an old school bike horn every time you try to stop. I pulled a Fred Flintstone stop on a few occasions just so I don't scare a dog or a child on the trail.
How would an individual rate something like this?
Are we equiping the same bike with 6 different rotor combos and rolling the same rider down the same hill and evaluating single and repeated stopping efforts?
So the rotor looks great and does not squeal as much as the RT81 (with the same pads).
Until some outfit (Bike Radar, et. al.?) does a comprehensive test, if you want shimano, get ICE Tech and buy based on price and what aesthetic you like, bc the Ultegra version looks good as does the original RT99.
I put these on my gravel bike they work very well. They are 140 mm and I am 210 pounds and they get the job done. I have another gravel bike with the same frame and fork but a different setup. It has 160 mm rotors and of course that has more stopping power but it's a different bike for a different purpose. If you are running 140's then these are the rotors for you.
Truth be told, do you really need dura ace discs? Probably not but they sure look good. Braking performance seems just as good as ultegra discs but with the black finish. Definitely not disappointing and at a good price too.