I'm the one who posted the Winhere thread. I bought those rotors because that's all I could get my hands on that day. If I'd had more time I might have waited for different rotors- Balo or maybe Zimmerman. But the Winhere rotors are working fine. I bedded in my Hawk pads on them pretty aggressively and not a trace of vibration or noise after 500 or so miles.
That being said, you never know what you're getting these days. I'd always bought nothing but Zimmerman rotors for my track 911. But after breaking two of them in a year, and hearing others tell me the same thing, I changed. I'd had good luck with Zimmermans on my track 911s for years but all of a sudden they've become less reliable. I also used nothing but SKF front wheel bearings for decades on the 911's but this past winter I couldn't get one to slip on the spindle. I pulled out my digital caliper and measured them and they were out of round. I had 6 sets in my parts bin and measured them all. 2 were bad- the first one that was out of round and a second one that had an ID that was smaller than all the others. The 4 good ones were made in Germany, the two crappy ones were from Indonesia. What I'd thought was a good German company was sourcing some of their parts from the far east and the quality control was junk.
2004 E53 X5 4.4 Sport
1997 E39 528i
1986 911 Track car