From the Introduction in the PDF
The Definitive Guide to Creating Robots and Androids
From Commander Data to the Metal Men, from Jim Lee’s Spartan to Cherry 3000, from Masumunie Shirow’s cybergeishas to George Lucas’s C-3P0 and R2-D2, from the Vision, to Jomi Shimodo to the Terminator, fully robotic heroes and villains have been a staple of comics and sci-fi for years. Unfortunately, the robots built using the system found in the D20 Future core rulebook can almost never be as compelling or competent as organic heroes. Very few robots built with the D20 Future rules will ever be as smart, creative or dynamic as their human counterparts.
Synthetic Heroes expands on the free form character creation system found in Fursona: The Definitive Guide to Creating Anthropomorphic Characters, modified slightly to build androids and humanoid war machines instead of cat girls and dog men.