I don't see anything unusual about the hub area. I do see that these are slotted rotors with slots cut into the friction face. The intended function of slots in the rotors is to allow gasses that form from very hot pads to vent off so that the gas does not build up a barrier that can degrade braking. That was a problem in days long past. The formula's used on nearly all brake pads today don't have the gas problem. That makes the slots unnecessary. Some would say that the slots may cut brake pad life by slicing off a little bit every time the pad hits the slot on the rotor. Personally I doubt that the wear difference is significant. Some like the looks of the slots, especially if they have wheels that show a lot of the brake. If you look back on past postings, you can find a lot of discussion about slotted rotors. The factory rotors for the SVT are not slotted.
On your original post, I thought you were talking about a difference in the design of the vents that are between the friction faces, and answered accordingly.
