"The Secret of Saurus Rock", "The Big Freeze", and "The Stone of Cold Fire" are my concerns with him. In my opinion, those are the worse in the series, and only #5 and #9 turned out truly watchable under his care. #10, while I do like it, could have been better handled, by a lot, and #11 was merely "just okay", as well. Roy Allen Smith was much more respectful of the world that Bluth and co. created.
If we were filmmakers, I'm positive that the more abled people of this chatroom would be the best thing to happen to this series in a long, long time.