Steve Mezak has posted a book review, at the end of which he states, “The bottom line is Mental Models is another tool you can consider using in your situation to discover and capture what your users are thinking. It can help you design a more user interface that has a better chance of delighting those users. However, it is not a replacement for even the minimum of specifications you need to provide a global software development team.”
Yes, I agree, it’s not a replacement for specs with a global software development team. It can sure strengthen the understanding between distant team members. Stories are a common cultural part of all human societies; thus the stories told by reviewing the mental model with remote teams (by telephone, recording, or written text) deepen understanding of the end user. I haven’t actually used a mental model with a development team in another country yet, so when/if you use it, I would love to hear how it works and where you need to change the method.