I haven't had a single problem with FC3. FC1 and 2, however, were different stories. The only problems I've had w/ FC3 were when doing my own kernel. Of course, I've used FC1, 2, and 3 so I probably knew what to expect when and after I installed FC3.
I might be a little biased. I am apparently a Redhat/Fedora fanboy. (yes, I'll admit it)
Of course in less than 2 weeks FC4 should come out. Can't wait til then.