It's been quite a small bit of time, now, but IIRC I had some direct correspondence with the author/creator of Readable, and he was a quite agreeable chap. I realize this doesn't speak to the technical merits, but the exchange left me feeling more comfortable about using his product. (Leaving aside the role of advertising and the need to support sites, a separate but not insignificant concern.)
Here's the old URL/site, which is also more visible with Javascript disabled.