Top 3 Reasons to Upgrade your Shopping Cart from Drupal 5 to Drupal 6

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?



Having built many e-commerce sites, though only a few with Ubercart, the #1 reason for upgrading is for the security of PHP 5.3. Running D5 with PHP 5.3 is a bit of a headache. Your reason #2 is spot-on. No one wants to see their site hacked and customer information exposed. Sticking with D5 greatly enhances this opportunity. Another good reason, is that the usability between D5 and D6 for the site maintainer, I feel increased dramatically. You can run Varnish and MemCache with D6 as well, enhancing perceived speed for the customer.