I see that Jelsoft is eating their own dog food by using 4.0.3 in production. In my opinion, no dot-oh release is a production release. I guess they could have called it 4.0 Preview Release 3 and everyone would be happy.
Those running 4.0.x - I notice a redraw "pause" when you go between different areas. I read a bunch about performance and with my users, that is more important than a snazzy new UI. What version is vbulletin.org running as I don't see the same issues here?
I agree on the feature comments but from what I see much of this will get ironed out a few 4.0.x releases down the road.