Our sports association website, PEICurling.com, like many websites these days, also has a complementary Facebook page (facebook.com/peicurling) (and Twitter feed @peicurling). We wanted to be able to quickly and automatically update our Facebook page with the contents of our website news items. As well, we have been accepting comments at both our website and our Facebook site, which has resulted in disjointed conversations where some people respond on one, and some on the other. We had been searching for a way to keep the comments in sync on both sites.
I am happy to say that Wordbooker meets both these requirements. We had been using "Networked Blogs" to send our WordPress posts to Facebook, but the posts often took several hours to arrive, making it not very useful for our Facebook followers. With Wordbooker, the posts arrive instantly (we use another plugin to send our Twitter updates). Wordbooker includes the ability to post to the Facebook wall and/or as a Facebook status update (we use just the wall), and it works with both Facebook fan (business) pages and personal pages (some products I tried only worked with personal pages). If you wish, you can also send WordPress pages, as well as posts to Facebook. I do this occasionally, and have the box turned off by default, checking it only when I want to send the page to Facebook.
The ability to keep posting comments in sync between WordPress and Facebook is extremely useful. The syncing process is not instant, as it runs automatically at regular intervals (I have it set for 10 minutes), but it works well, and lets both Facebook and WordPress users see the same comments, regardless of where they were posted.
Wordbooker also has the ability to include Facebook "Like" buttons (I currently use other products for this) and has the ability to show fairly detailed diagnostics. It also comes with a 33 page user guide, which is rare to find in a free plugin.
The product is not without its glitches. First of all, it's working with a moving target, Facebook, which makes changes without notice, has unresolved bugs, and also with third party Facebook apps and WordPress addons (e.g. Jetpack) that can also introduce conflicts when they are updated. This sometimes results in the Wordbooker programmer having to make quick fixes, which he always manages to do in a reasonable timeframe. Secondly, the posts occasionally don't arrive at Facebook, and require a resend. I assume this is some sort of timeout issue at Facebook's end.
I have another site, configured almost identically to PEICurling.com, and have been able to get the post sending capability working, but not the comment syncing (the process runs, but never finds comments to sync). I haven't yet been able to resolve the issue, but the ability to send the posts still makes it worthwhile.
In short, when it works (and it usually does), it's a great product, especially considering that it is free, and that I haven't found any other plugins that do comment syncing in both directions.