Mark I still use vb 3.0.3, and haven't upgraded since then cause I was and still am happy with everything that it has to offer. Recently I was looking to upgrade to 3.5 but looking at how much work I have to redo, it's almost not worth it. I mean I know that the ajax features are nice, but the plugin or the hook system wouldn't really affect me. But my point is that I wanted to upgrade to 3.5, but it seems that 3.5 is a whole different system with a lot of code changes, it would take me a lot of work and money to upgrade my board to 3.5 which I can't do.
But I'm happy to find posts like this and read what some have to say about 3.5 though, I wish they were more