I am using ErWin to design, forward engineer the database code and produce DB documents using the Crystal Reports edition embedded in ErWin.

Hardly ever do I need to customize the ERwin-generated code once I have set up the proper options for each model (such as macros for generating constraint and index names).

Huge time-saver when making changes and keeping documentation consistent and up to date.

Diagrams are a great training aid and very helpful for evaluating enhancements.

However I typically get blank stares when I discuss the value of an ERD tool for DB projects, even with experienced developers.

I wish I knew why, my best guess is the learning curve. I admit it took me quite a while to reach the current level of productivity.