Thanks for the input! Following your post, I tried to see if Amazon will accept fractional values for the ratings filter and unfortunately the answer is no. You are right though -- it would have been a great idea. As to your second point, I can probably add the actual average score overlay when you hover over the stars, but I am not sure if I can do the breakdown, this data is simply not available from my data source. I will work on adding that overlay in the coming days. Thanks again for the suggestions!
Just wanted to let you know that I have implemented your suggestion related to more granular star ratings. The granularity of the star icons is now 0.1 stars and I also added a tooltip that shows the numeric star value when you hover your mouse of the star icons. You may need to do a full refresh of the page (Ctrl-F5 in most browsers) to pick up the new code. Check it out an let me know what you think!
Looks good - thanks!