I have used RH4 up to FC8..
.. and finally got seduced by Ubuntu, cos FC7 registered itself as 6.9 and refused to update anymore (with ANY package manager). Even though this was a trivial issue to fix, I was just so annoyed at the idiocy of it, and left it all behind.
I do miss FC/Red Hat. I will be trying FC10, but if I can't get my nVidias running and my laptop's non-intel wifi without jiggery-pokery, then I will need the 10-foot pole to push it away.
x)