It was no problem - I even set up a test site/database to ensure it - there were a couple small issues, but nothing that couldn't be resolved. And best yet, my 3.0 style transferred to 3.5
Most people are saying go to 3.5, can you explain why? I mean is it worth the headache of upgrading for features I won't use?
You'll probably use more of the features than you think you will. 3.5.0 is the only way to go. The plug-in/product system alone is enough reason to upgrade.