Schiller is average at best in presenting, but Jobs is a different story. He connects real well with the audience, and he doesn't confuse the subject with too much technical jargon; it's a very understandable format.
Jobs is one heck of a presenter, if not a great salesperson. One way to identify a good salesperson is to see how much passion he or she has in the product they're selling, and Jobs holds nothing back. Compare that to Gates, who's the biggest dryball in terms of humor. He's good at pointing out features, but he doesn't do a great job communicating the benefits of his company's technologies. Jobs does, and he does it well.
Now the questions about ego is a different story.... 😀