I can definitely relate to the time aspect mentioned here. I find that for very complex design or architecture issues it can sometimes take an hour just to "load" the problem into my memory, such that I can then start thinking around creative solutions to it. I just couldn't do that in the typical open plan office.
This is absolutely true for me as well - since working from home in Nov, I've noticed the quality of my work has gone up even more than the quantity because I can concentrate on just the output rather than being self-conscious about looking like I'm working during the runup to the output.
As a designer, for example, I've hit stumbling blocks with certain layouts and now that I think about how I've often solved the problem, I'd probably get tossed to the curb as a weirdo from even the trendiest of open plan offices - I'll list all the UI elements on a sheet of paper, then go lie on the couch for an hour or so and mull them over in my head to let it marinate, maybe go to the corner coffeeshop to read the paper to get my mind off of the gig but with index cards and sharpies by my side in case an idea occurs. I can't isolate when or why, but sometimes that's way more productive than just staring at an empty screen or trolling through CSS gallery sites.
We are different and a lot of "these" matters are subjective. E.g. some use Vim while others use Emacs and some people prefer to work from home while others prefer to work from an office. What's better is not that objective and people should do what they feel best with.
What can be very frustrating in a corporate environment is the unrelenting "one size fits all" attitude. Your workspace. Your toolset (not just what language to use, where I can understand a need to standardize, but what editor and utilities and such). Your flexibility is limited to what pictures you put on your desk.
For me, the distraction in an open space environment kills my productivity. I don't want to be disconnected from my coworkers, but I can't take the constant noise and immediate presence. I get along much worse in such a situation. Give me a little separation, and I'm much more relaxed and focused in face to face meetings, on the phone, in email and IM.
When things are like this, I do quite well. Then something will change and the work environment will suck again. I'll tell my management exactly what has happened and why my productivity has declined. But there is nothing they can do. "But we all work in cubes" is one response I received.
One size fits all. If we do it for you, everyone will want it. We must treat everyone "equally". In the name of "fairness", they force department management to turn a blind eye to individual variances and differing needs.
At least working from home seems to provide some disconnect, in the company's mind. The home environment is not their jurisdiction, and your performance is measured more in terms of results rather than conformity.
One suggestion I have with regard to open space: If you insist on it for your employees, then let them self segregate to some extent. There is always a subset that wants a quieter work environment, but they are spread throughout the organization. Let them colocate in a designated quiet area, akin to the "quiet floor / quiet hall" arrangement at some colleges and universities.
I suppose this would be viewed as overly burdensome in terms of management. Further, I've observed a continued strong drive to physically colocate team members whenever they are at the same facility. But it would take no more physical space, and it would make that portion of the population much happier and more productive.
Next step, let them use decent tools. Don't force them to do finger gymnastics because you keep them on the 5-releases-past version of some commercial editor that has been "blessed". But now I'm just dreaming...
Speaking about the "concentration span" I can't but notice that sometimes it's very easy to get lost when you are overly concentrated. That's why it is extremely important to discuss new ideas, algorithms or implementations within the team.
You physically reduce possible sources of distraction when working from home, but you still need to work hard to improve your concentration skills.
That's why I think that a good office ( the one with some private and quiet space for developer) + good discipline ( reserve some time for hanging around and talking, be concentrated all the other time) will work way better than working from home.