I bought this (it's cheap) and used it on my "Urban Love Affair" song recently.  I wrote a review of their product and gave them 4 out of 5 stars because there is no metadata in the MIDI clips (hard to know which clip you used once you insert it into Sonar) and some of their folder titles have the wrong info about what key it's in.
 
Apparently they only post the 5-Star reviews, as my review was taken down a few days after it showed up.
 
The chord progressions are somewhat gospel-y and lush.  They do sound good and are useful to us non-keyboard players.
 
http://www.tru-urban.com/the-r-b-chord-progressions-midi-library/

Thanks Tony.....I certainly fall into that non-keyboard players list and I'll definitely check this out at home. It's a blocked site here at work.