Add-on is great. But if you're new to amazon s3 and cloudfront, think long and hard about using this add-on. The installation instructions are lacking and outdated. I'd give it an excellent mark if the support to get the add-on to work properly was better.
I have to review again to update how I'm using this awesome addon. With this addon I successfully and easily transferred 80GB of attachments (about 400k files) to the /data directory. Which means, now all my attachments are being served by my CDN along with everything else in the /data directory. Wohoo! So far my CDN bandwidth has quintupled and is still rising... but that's a good thing :) Thanks xfrocks.