To illustrate this point, React min+gzip is about 40 KB: https://cdnjs.cloudflare.com/ajax/libs/react/0.13.3/react.mi... not 121 KB.
After doing some research it looks like larger libraries with more redundancy will benefit more from gzipping than smaller libraries. So relative to uncompressed file size, React will be compressed more than say Backbone.
Definitely going to add this in. Thanks again.