With UML 2 you can convey more using your diagrams. So I would suggest you to go ahead use a tool that supports UML 2. I have n't used UML 2.0 features for Class and Component diagrams, but felt the need of it for sequence diagrams for presenting the alternative flows. so I have used a tool based on UML 2 only for sequence diagrams.
Joined: Nov 28, 2005
I wanted to use the UML 2.0 exacly as you said for sequence diagram, because is more easier to express the alternative flows and the "included" usecase.