Let me attempt to broaden and slightly critique the version of productivity this thread has been considering so far. It seems somewhat limiting to discuss productivity solely in terms of what content makes it into an article. For one, this assumes that articles are somehow independent -- text that is reverted from one article will not reappear in another article. For some articles this is an ok assumption, while for others its way off. We've observed editors who push their viewpoint across a wide set of thematically related articles.
This way of considering productivity also does not account for how seemingly unproductive edits may impact the editing process (meta impact if you will). As one example, a controversial edit that is eventually reverted may generate insightful discussion on the talk page. This discussion can impact future edits (and not just on the same article). To be more concrete, highly controversial pages (e.g. Jesus) maintain oodles of archives of discussions (many of which originated with controversial edits). Newcomers are socialized into the practices surrounding an article by being pointed to these discussions whenever they bring up topics that have been extensively discussed in the past. I would consider edits that generate such discussions to be productive.
A reverted edit on an article page may be productive in other ways as well. For example, it may spark discussion that leads to edits to policy pages. And I'm completely at a loss at how to evaluate productivity of edits in the WP namespace. Word count may be an ok proxy for completeness of an article on a topic, but it is clearly the wrong productivity metric for things like policy pages.
thanks, ivan.