The MicroPC is great because it makes it super easy to code and hack on something in places where it would be too awkward or annoying to whip out my laptop, and the Cardputer is just a fun little toy because it's so open ended and hackable. I've been writing an app for Cardputer to control my thermostat remotely, and I've had a lot of fun grossly overengineering the needless amount of concurrency I have added through FreeRTOS.
Something oddly satisfying about using a micro PC to program an "even more micro" PC. What a cool time to be alive; I would have killed for this kind of stuff as a teenager!