I have to add that my experiences with Fedora have been excellent. RedHat9 ---> FC1 was the transition that truly allowed me to migrate completely AWAY from Microsoft. And I have FC2,4,5 and soon FC6 running my digital life. In the cases of MythTV and understanding RHEL through free software, Fedora Core is truly a great and resourceful distro.
Ubuntu is good too. I have used it on many occasions, but the FC user community and availability of troubleshooting docs (via Google searching) is by far much more effective than Ubuntu.
I do agree that the bugs in FC releases have been pretty hefty, but Red Hat ?touts? FC as the bleeding edge. No mistake there. My advice is to run the latest Core versions with caution and give a month or so for things to work themselves out.