My website (http://www.FighterWarehouse.com/) is hosted with Volusion, which charges an arm and a leg for bandwidth. So I decided to host my product images off site with Cloud Files to save on all the BS bandwidth fees Volusion charges. I also chose a Rackspace solution because (true or not) I figure that since Volusion is hosted with Rackspace, it might be fast to have my "off site" images hosted at the same place for speed sake.
Anyway, the setup wasn't nearly as easy as I thought it would be. They didn't send me any email with login instructions so I had to get it from their chat support which proved to be very helpful though.
I was surprised that it was not as easy as FTPing some files and quite a few of their help pages talked over my head.
Finally I got it installed properly, I think. To all the Volusion users, I'll re-post after a month or two of traffic to let you know if it reduced my bill and how it affected the load speed of my site.
Overall, I'm giving this a 4 rating because their introductory email could simplify things a little for use, also the price, the service itself, and the help desk attitude are indisputably great.