Differences in brakes between B8 and B8.5?

[viceroy1976]

Is there a difference in the front rotors and pads between the B8 and B8.5 S4 that would not make them interchangeable?
Looking at the EBC catalogue, the B8 rotors are GD1571 and the B8.5 are GD1844 with a massive price difference between the two, but the rotor dimensions are the same.
Thanks

[MrFunk]

As far as I know they are interchangeable.