The recovery drink is a different formulation in that it has a higher protein content.
The theory here is that after long rides, when your blood and liver glycogen levels are zeroed, your body goes scavenging for calories where it can. It will get a high proportion from body fat but protein breakdown will also occur hence your muscle tissue is actually subject to being metabolised.
To repair damage to body tissues that takes place after all exertion also requires protein.
so i think there is good nutritional theory behind having a recovery drink but only after very long rides - say 50 miles plus; shorter rides don't hammer your resources enough.