I tried hunter back in beta. Then I tried hunter again around last Christmas.
It must be the most boring class ever in any game. Even more boring than mages are in WoW, and that is a lot said... Pew pew kill. Pew pew kill. Pew pew kill. Pew, oh shit I did aggro three mobs, "You have been defeated".
Loremasters are ok. Sort of weird, but sort of fun too
Guardians I won't touch again, they really felt like they should be played together with somebody else. Then again, haven't tried either since the early days of LOTRO, so things might have changed quite a bit since then.