I enjoyed them a lot. ANH had a bit more info than was in the movies, which was nice. ESB was closest to the movie, I'd say. ROTJ had quite a bit more in it that we didn't see in the movie. I really liked the extra dialogue between Vader, Luke and the Emperor, especially pertaining to Yoda.
I also enjoyed "Splinter of the Mind's Eye." Not great, but definitely good. Some nice foreshadowing in it with the limbs being lopped off, and it was interesting to see the relationship between Luke and Leia, considering certain things hadn't been answered yet.
P.S. I love that Zangief baby attack!