[aendruk]

> They like it because they're very non-technical people, but totally get spreadsheets.

My experience matches this. About a year ago I rigged up Google Spreadsheets as a data source for Middleman in order to streamline content updates from the client throughout development. I learned the hard way to use fuzzy matching when correlating client-editable record names between data sources, but it otherwise worked well for both of us.