I've read a lot of these things, and while I recognise there is some research in favour of private offices, I also think it's currently very 'trendy' to say that open spaces are bad, and I think a lot of the discussion is very developer-focused. Most of the people in our office are non-developers, and while the developers like quiet, our creative teams get far more enjoyment (and seemingly productivity) as a result of being able to talk and bounce ideas off each other much more.