They are better than an open office plan inside of a company - because those people are collaborating more loudly and feel that as long as it's on topic it's okay to be loud. Generally a bunch of professionals working on different things are quieter than that. It obviously won't beat a dedicated office, though.
I use headphones but i don't mind people talking around me, sometimes it's energizing. Obviously you have to choose the right one.
Good thing is that you can also just try them for a week (and that's what i did at the beginning)...after a while i decided to co-found ShareDesk. :P
You have to find the right one, but YES, they are definitely places where to be more productive. Try!