My 2009 F800 GS was in the shop today for a 12K mile checkup. I was told that my rear brake rotor was under minimum spec at 4.43 mm and should be replaced. The cost? $300 plus. I was none too thrilled to hear this and asked "how common is it for an F800 GS to need a new rear rotor at 12K miles?" The answer I got was vague. I decided not to have the work done. I want to gather more information and likely will replace the rotor myself possibly with an after market brand. Has anyone else had to replace their rotor this soon? I did a search and did not find discussion on this but surely this has come up. What are others experiencing with rear rotor wear/replacement? Any feedback is appreciated.