I recently spoke with a client who has an e-commerce website built with Drupal 5 and Ubercart. I sat down to write the top 3 reasons to upgrade your website from Drupal 5 to Drupal 6. Since Ubercart for Drupal 7 is in Release Candidate3 status, it's not ready for production use.
1. Many of the features you are asking for come built in with Drupal 6
- one step account sign up
- auto fill of billing address at the checkout
2. Drupal 5 is no longer being supported by the community. There will be no futher security updates or bug fixes released for Drupal 5. Everyone is encouraged to upgrade to Drupal 6 to take advantage of the latest versions of Drupal core and contributed modules. This increases security and gives you access to new features not available in Drupal 5.
3. It is more costly to support a Drupal 5 site. All new features and bug fixes would need to be custom programmed.
What are your benefits to upgrade from Drupal 5 to Drupal 6?