I've hiked the northern Catoosa and the Frozen Head sections. Both of those were very well marked.
I've really considered doing section hikes from Cumberland Gap south thru Frozen Head. I haven't been able to find anything updated on the trail conditions for the section from Cumberland Gap to LaFollette. It was open at one time but from what I understand had a bunch of trees come down that were never cleaned up. I turkey hunt this area and have been meaning to check it out. Just don't think about it while there.