It’s difficult to find an informed concise review and comparison of these two elearning software packages in their current versions. This review is the best I’ve found to date that gives those with less than expert level on both an informed viewpoint. I have a good working knowledge of Captivate and I’m learning Articulate Storyline which I really like.
If I had to choose between them I’d go with Storyline for Rapid Development and publishing though Captivate integrates well with other Adobe products which can be appealing to advanced developers.
Read the article and form your own opinion.