Pololu makes a controller (called the “Baby Orangutan”) very similar to the one I am building. It has an Arduino-compatable microcontroller, 1A motor driver, and user IO lines. It is also cheap. However, there are a few things my design has that theirs does not.
The ToyBrain motor driver is replaceable. If you accidentally short the output pins and destroy the chip with overcurrent, you can remove it from the socket and replace it. The motor driver of the Baby Orangutan is a fairly fine-pitch SMD package, and so is difficult for the average user to desolder and replace.
Connections to the ToyBrain are also a bit more convenient than those on the Baby Orangutan. The ToyBrain has headers designed for servos, and headers for sensors that carry power for those sensors. The Baby Orangutan breaks all the pins out as single pins, leaving the user to deal with power wiring.
The ToyBrain uses the serial port for programming with a $5 FTDI cable available from multiple vendors. This means that it integrates very easily with the Arduino development environment, and it can send serial data back to an attached computer. The Baby Orangutan uses a USB to ICSP adapter to program the chip. It has the ability to send data back to a computer via serial, but it would require a second cable.
This post isn’t intended to slam Pololu. They make useful products with incredibly high quality. I know this because I buy their stuff. The point isn’t that my device is better, it’s that it’s different, in ways that make it better for me.