The above page tells you the difference between the Rico & Rico Royal. Looking @ the Rico reeds I have it seems the Rico Royals have a straight line of bark or outer reed surface removed above the usual curved slice that the ordinary Rico's have. That would probably make the reed more flexible in the thickest part of the reed.
Ordinary Rico's have an American style cut & Rico Royals have a French cut for faster response
<Added>Oh it looks like the link did not work. Just type "Rico Reeds" into your search engine & find the Rico website
