Very nice, but I think you should put somewhere on the website what Class A, B, C, D and E mean. It's not on the main page, and it's not on the "Learn more". This is something very interesting to know though...
Also, due to how the web looks in recent years, my mind is trained to ignore anything containing Facebook, Twitter, etc... at the bottom of webpages because it's usually meaningless footer content. However the "Ratings" part on your site looks exactly like that. I only discovered the second time that it is content.
If more people unconsciously ignore such stuff, you may want to present it in a different way.
Also, due to how the web looks in recent years, my mind is trained to ignore anything containing Facebook, Twitter, etc... at the bottom of webpages because it's usually meaningless footer content. However the "Ratings" part on your site looks exactly like that. I only discovered the second time that it is content.
If more people unconsciously ignore such stuff, you may want to present it in a different way.