I have not used ERWIN because it was out of my budget. The tool I have used for forward engineering (and a little bit of reverse engineering) is an affordable ($135 to 335 per user) alternative that I would recommend to people investigating these tools: Enterprise Architect. It is not dedicated to just database diagramming but the Professional version (which I own) does the database diagrams and SQL DDL work very well for SQL Server. More information can be found at http://www.sparxsystems.com/