I did one better than that, I shot my ST Micro rep an email and asked them if they would like a open source design on the web that showcased their new STM32F4 series with built in Wireless support and their new STSPIN BLDC controllers with built in Cortex-M0s. He was quite taken with the idea :-)

Quadcopter pilots have been using STM32F3 for years. Check out: https://github.com/betaflight/betaflight one of the more popular flight control projects. They've been supporting STM32F4 and STM32F7 for quite some time.

A typical quad flight controller with an STM32F4 and a decent MPU will set you back less than $30.