It's hard to rate something when you're clearly not the target audience but as someone who's on a mission to "complete Star Wars", I left this series to last.
As an adult, it's utterly painful. As a kid it may be entertaining enough I guess.
For those wondering, it adds absolutely nothing to the "The Star Wars story" but I don't believe that it was ever intended to. At least in Droids there were some (although not many) references to Star Wars. In Ewoks, there's absolutely none. None of the creatures, music, environment, music, nothing. At least the films had a little bit of Star Wars in them.