Hmm...well, I don't really know what to say about the two. The first movie would definitely be different without them. In the second movie, they were just, to me, a comic relief, so to say,they didn't really add as much to TLK2SP as they probably could have. And honestly, for me they just weren't the funniest things in the world, or the movie. :3
Even though I love "Hakuna Matata" and, like I said before, a lot of TLK 1 (after Mufasa's death and Simba runs away from the Pridelands) would have been different without them, I'd just have to say I don't like them much at all.