If you do a web search on "articulate versus captivate," you will find a lot of opinions about how the two programs compare. One of my clients asked me about the merits of Articulate versus Captivate. The answer that I gave him is copied below. I hope it offers a different perspective for you when deciding between Articulate and Captivate.
Ah yes, the great Articulate versus Captivate debate. Ford versus Chevy, Coke versus Pepsi, Yankees versus Mets...I'm kidding about that last one. The Yankees are, after all, a professional sports team.
First, I would recommend they get the 30-day trial before purchasing. It's fully functional and free.
Both Articulate and Captivate will read in a PowerPoint and then enable you to add interactions, audio, and quizzes to the presentation. Then, they enable you to export the resulting activity as a Flash file.
Articulate makes it a little easier to start with PowerPoint. I think it brings in more of PowerPoint's advanced features, such as custom animations. However, the other things that you can do in Articulate are a little more limited. That's because Articulate's raison d'etre is to take a Powerpoint slide deck from a subject matter expert and enable the e-learning specialist to turn it into an online activity.
Captivate lets you add more features. It also enables you to take screen shots and full motion video of your screen and add it. Captivate just does more. And, it's more popular among e-learning specialists.
If your client is starting with a subject matter expert who knows just basic Powerpoint, then either tool will do. If the SME knows advanced PowerPoint, and will supply them with a slide deck that has advanced features like custom animations and timing and embedded files, then go with Articulate because it interfaces better with PowerPoint's advanced features. If your client wants to be able to create e-learning without PowerPoint, and start right from within the tool, then try Captivate.