C++ FAQ Celebrating Twenty-One Years of the C++ FAQ!!!
(Click here for a personal note from Marshall Cline.)
Section 13:
[13.2] What are the benefits of operator overloading?

By overloading standard operators on a class, you can exploit the intuition of the users of that class. This lets users program in the language of the problem domain rather than in the language of the machine.

The ultimate goal is to reduce both the learning curve and the defect rate.