It depends on your preparation time. The best talks, IMO, are those written out in detail and completely memorized through many practice sessions. If you only

It depends on your preparation time. The best talks, IMO, are those written out in detail and completely memorized through many practice sessions. If you only do 2-5 practice runs, you're probably better off with an outline-based or extemporaneous approach. If you do more, say 10-25 practice runs, the script-based approach becomes very effective because you can deliver it naturally from memory without pauses or confusion. It sounds like your guy probably only practiced his talks once or twice, if he practiced at all. It's tempting to view a script as a way to minimize practice, but really it's just the opposite. It takes more practice to refine the script and to present it naturally.