AVR Butterfly Opinions?

[Asellith]

I was planning on building my own base unit for my HVAC controller project but the AVR butterfly looks like it does everything I need. It even has I2C for connection to modules from the SOR open Source module project. I can add more temp sensors for individual rooms and a massive servo controller as well. So I was wondering if anyone has played with this before. Looks really good for $21. Even has some ADCs and a LDR.