Do I really seem to have read most of them? Fantastic, what a blag! I've only got Lost Tales 2, Lays of Beleriand and the Lost Road. Never read any others either.
As to whether they're any good, it depends on how much of an obssessive fan you are, as they are just notes and early drafts for what would later become the major works. CT's annotations are overly long and dull, and you do have to read about 99999 different versions of Beren and Luthien and Turin etc. etc. But it's worth it to get into the mind of a genius, and try and work out what made him tick.
Hard going, but quite rewarding, would be my opinion. Good luck Hannum4! :)
http://www.plasticsquirrel.co.uk for all your bizarre music and musings needs