Rev 7 is now available for the C300, I have just upgraded all 3 of mine and the procedure was fairly straight forward and easy to do, all drives had data on them, no harm done and working well.
As for the Marvell, forget you even have it ! run them on the ICH10R.
Those of us who stepped up from RE2 to RE3 thinking we would get Sata 3 6gb/s were ripped off, it does not work.