Also, the Carambola is readily available now, for the RasPi you'll have to wait months on pre-order (I must've waited 3 or 4 months before I had mine shipped to me).
For me the Carambola is kind of the missing link between microcontrollers and powerful ARM boards like the RasPi.
And speaking of powerful ARM boards, Graperan is making a new one as well (4418-Graperain). Equipped with a 1GHz ARM Cortex A8 CPU, 512MB RAM and 4GB Flash ROM
https://www.graperain.com/ARM-Single-Board-Computer/ ... for real power hungry embedded applications.