Only difference between Studio 9 and Studio 10 is support for burning BlueRay so unless you've got a BlueRay burner I wouldn't bother. I've got both versions (free licences from a while ago) and agree that it's excellent software. Particularly like the cover printing facility.
Spot on, no DVD authoring. Which is also the only disappointment I have with Ashampoo 2010.
Removed Nero 6 which was the latest version I had in favour of a more up to date Ashampoo. Fortunately was able to restore Nero's Vision Express on it's own to compensate for the absence of DVD authoring.