As Six mentions , a couple of riders on here like myself , run the ductile iron rotors , Braketech make . The ductile iron is new tech compared to the old iron rotors used on example old Ducatis etc. The ductile iron is still ideally recommended to use organic pads , ceramic , but I have run a scintered pad with these Brakeechs .@ROADTOAD1340 has iron rotors on his gen2, and he speaks highly of them.
Both my Busa and Kawasaki currently sport the 330mm iron rotors , though they are heavy compared to a lot of disc options , and compared to the stockers .
Recently scored a set of Brembo T drive 320mm for the Kawasaki (yet to fit and try them out ) in stainless . These are lighter than the Braketechs , but heavier than the stock petal 310mm rotors .
The ductille rotors are prone to surface rust when left wet , but next ride cleans them up . The bite of the 330mm dinner plates , along with good calipers etc. is something to experience , but I am currently fixated on reducing unsprung weight off the Zed14 , and still thinking about going for some even more super light rotor setup .