I am close to replacing the rotors with OEM ones. They have done the job well enough with the right pads so far. I was thinking about the PFC rotors, but will leave the car stock fopr the time being. I was also going to put in some brake ducts, but despite getting all the bits, decided not to start hacking holes in the car for about 1 year's use and a few track days.
I thought I would need to swap rotors now, but I have some time left. They are about 75% used based on the starting thickness and minimum thickness. They have ~15 track days on them plus ~20K miles. I will check them again before the next event to make sure they are okay. There are no signs of cracking at the moment. My last set got micro cracks and they were swapped under warranty. I am on the conservative side with replacing worn items.
I am now planning in getting the next gen M3 next year, rather than a late E92 (unless there are awesome deals before that)