Great product for rapid SharePoint design and impl
The IntranetFactory Modeler is an excellent tool for SharePoint prototypes. It is intuitive, easy to set up, and most importantly, it works.
If fast prototyping and implementation is a high priority for your company, then you should take a look at the other (non free) products provided by IntranetFactory. I went this route and am very happy with the results achieved as well as the level of support I received from their technical staff.