I have seen these at Autocross series that I race in. I can tell you my friend's explaination of them. He runs a fully stripped and prepared Evo (pic at the bottom of the post) and for the season he came in 2nd in overall index and first in XP class. So the car is very good and he is a good driver as well. We have talked about the brakes and he considers them to be:
- made for weight savings
- small performance improvement over stock brakes
- he would not run this brake setup if he tracked the car. it is a autocross only setup and this is one of the components he would have to upgrade to be safe enough to be trackable.
I personally notice that the 3 piece rotor design looks like it saves weight vs other kits.
Again I am not an expert in this brand, but just wanted to share what I have heard from someone who does race with these breaks.