Trying to wrap my head around the best approach in modelling a database when we are using Entity Framework 4 as the ORM layer. We are going to use asp.net mvc 2 for the application.

Is it worth trying to model using the class diagram modeller that comes with Visual Studio 2010 where you graphically configure your models into the EDMX file and then generate out the database structure?

I have run into a bunch of non trivial issues and for complex many to many mappings or multi primary key entities the answer is not that obvious even after poking around a while with the tools.

I figure its easy at this point to give up and start modelling the DB using real, working DB modelling tools and then try to generate out the EDMX from the database, rather than trying to do the model first approach.