I found this thread really interesting, as so many of the comments reflected my experience with CI and Drupal.
I’ve developed a few Drupal sites, including the student newspaper site for the college where I teach, I’ve read Drupal books, and I even attended DrupalCon last year. The last six months I’ve been working extensively with CI on a tutoring application. As Colin and others have said, Drupal and CI each have their strengths.
But for me, developing in CI feels less like work than Drupal, even though Drupal is theoretically more functional out of the box. Sometimes in Drupal it’s a challenge just deciding which of the half-dozen modules available for every conceivable task is best suited for what I need to do, especially when some contributed modules are dependent on other contributed modules. When I build something in CI, yes, it may take more actual programming time, but I feel like my overall decision-making time on a project is reduced, because at least I know exactly what I need to do and how to do it.
So it just comes down to how you want to spend your development time. Everyone knows Drupal has a prolific community of developers, but working effectively in Drupal practically requires that you keep pace with what’s happening in that community, and that takes time. CI requires more initial development time for things like CRUD and user authentication, but from there you can build just what you need. And the CI forum is active enough to answer questions and help with best practices and so on.