You're free to view the older revisions of this gist, but much of this content has been rewritten and will appear on the [Basho blog] (http://basho.com/blog) in the very near future.
Update: First part of the series is now at http://basho.com/understanding-riaks-configurable-behaviors-part-1/
I second @coderoshi's comment about "Under DW: "value be written to the backend" should probably clarify by comparing W does not wait for the backend to reply. Better to be a little too pedantic than not enough in this case."
In the "Readin' and Writin' (R and W)" section, it should emphasize that "successfully read or write" means X nodes have to acknowledge the request, but not necessarily write it to the back end (except for at least 1, since DW is set to a minimum of 1). Which is more confusing, but necessary to emphasize.