Whilst going through MS Project 2007 to identify differences from 2003 & 2000 , I noticed that apart from the improvements in look and feel (As usual for Microsoft!), there are some actual advantages. For example, there are improvements with regard to metrics and also reporting. Sometimes, VBA Code had to be written in older versions to change the reporting as required for different audiences as they were not provided by default which is tedious. (Finding people who have that skill is tedious as well)
I did a quick search to see the differences and found this page from Microsoft.