[Joeri]

In our company we combined the two, the developers sit in a large open floor plan which is a quiet zone, and to discuss something you go into a meeting room. The quiet zone is enforced through social pressure, a bit like a library reading room, except less perfectly quiet (people still periodically interrupt the silence). The result is a lack of team dynamics because people don't talk enough, AND a lack of personal productivity, because there are still enough distractions that you can't work for long uninterrupted stretches.

I've become convinced the best solution is the one from peopleware: 2 to 4 people offices, with a door.