The one result I've found most surprising from these studies is that open-plan offices tend to reduce face-to-face interactions. Trading short-term productivity against satisfaction is perfectly reasonable, but I worry that in practice the lack of privacy and fear of distracting others mean that open offices aren't even good for socializing.
What I've found very valuable for all the things open offices claim to do is having some shared open area that isn't a workspace. A centralized kitchen area or anything else that recreates the traditional 'watercooler' works for facilitating chance interactions and allowing easy socialization without all the hassle of talking behind coworkers' desks.
Cynically, it looks a bit like the 90s-downsizing-era push for productive spaces killed off watercooler discussion, and open offices are a kludge to bring it back a the pretense of productivity because people are at their desks. In reality, I don't think the connection is so direct, but I'd still prefer we admit that chatting and working are both valuable neither is well-served by putting them in one space.
Wrong. Extroverts like to interact. Not introverts. And the extroverts are usually who are put into positions of power, and think that everyone is like them.
It is sheer hell to work in IT and yet another cattle-class open office.
However, I think there are two other factors that come into play that are very tough for people to vocalize when they are defending an open office.
1. Open offices are more appealing visually to a wider swath of people. Of course you can make either kind of office pretty, but there's something about humans that just really loves the wide open spaces.
2. Humans are social, we like to interact, even at the expense of productivity.
Personally, I prefer an office-per-team approach, so sort of a middle ground that allows for fast collaboration but doesn't require negotiating with 100 other people on the same floor about noise level, etc.