Plone was very cool when we set the site up many years ago, but it’s quite quirky, and very heavy on memory usage. On a dedicated machine this is not a problem, but when I’ve been setting up sites on a shared server, I can run rather a large number of Drupal sites in the RAM required for one Plone installation. With hosting services like the excellent Webfaction, there’s a pretty direct motivation to switch. One Plone site needs more than the base-level service and so will cost you more per month than several Drupal sites.
Besides, Drupal is wonderful. I’ve investigated many CMSes over the years and I’ve fallen in love with Drupal. It’s beautifully designed, despite the fact that it’s written in PHP, which for me is a bit like admitting that I like The Matrix even though it stars Keanu Reeves.
Drupal’s power is not immediately apparent, but if you’re willing to put some time into it, listen to the podcasts, Google for the screencasts, explore the contributed modules (of which there are now thousands), your effort will be repaid. I was very pleased with how quickly I got Rose’s new site up and running, for example.
Anyway, all of that is a long introduction to the fact that I wrote a Python script which helped me convert Plone content into Drupal content and I’ve posted it on qandr.org in case it’s useful to anyone.