I feel they do a decent job with newer movie sequals. But that said, I really enjoyed Lion King 2. They showed how a sequal can be made. Didn't see Lion king 1 1/2 yet. But I did enjoy both Aladdin sequals (though I felt Aladdin 3 proved that the series borrowed WAAAAY too much from Indiana Jones) and Goofy Movie 2 (though it was mostly an ad for ESPN's X games).
Some of their sequals (Tarzan and Jane, Beauty and the Beast enchanted Stories, Atlantis: Milo's return) we basically just episodes of the series pieced together, even though most of them weren't produced as series (Atlantis had potential).
I kinda dug Chicken Little. Don't know how they'd sequal it, but it was a neat little movie. Enjoyable at least. certainly the only solo CGI effort that wasn't as bad as the others. Dinosaur put me to sleep.