I know that members on this list are dubious about using personas in
the design process.
Here's a nice, solid research paper by Frank Long at NCAD in Dublin
that shows how they can improve team dynamics:
> Real or imaginary: The effectiveness of using personas in the > product design process. > > As you know, the use of personas as a method for communicating user > requirements in collaborative design environments is well > established. However, very little research has been conducted to > quantify the benefits of using this technique. > > The aim of this study was to investigate the effectiveness of using > personas. An experiment was conducted using students from NCAD. The > results showed that, through using personas, designs with superior > usability characteristics were produced. They also indicate that > using personas provides a significant advantage during the research > and conceptualisation stages of the design process (supporting > previously unfounded claims). > > The study also investigated the effects of using different > presentation methods to present personas and concluded that > photographs worked better than illustrations, and that visual > storyboards were more effective in presenting task scenarios than > text only versions. > > The research: http://is.gd/I5Zk