Over the last few months I have observed a number of projects proceed badly because of the early use of templates in the process. Yet having a template is much better than having a blank page to start with.
Unfortunately starting with the template kills creativity and actually takes longer than starting without a document template.
Templates and worksheets can be a helpful way to document a project but filling out document should never replace creative thoughts. With Powerpoint, you can create good and bad presentations, but that's not Powerpoint's fault, is it?
Great post on the creative aspects of product planning. Think first, support with templates later.