Beagle Bone Black and Cubieboard are wayyyyyy more powerful and more stable (I'm testing the BBB for months, incredibly stable, and the Cubieboard for like a week only).
I don't imaging running my miners on RPi anymore, they are not as stable (I think it's because of the SD Cards... both BBB and Cubieboard have embedded MMC).
SD card is problem with RPi especially if power is not stable. If power goes off SD card gets corrupted almost every time.
I don't like Cubieboard, drivers are not open source and support is not close to RPi. HW is stronger but without good SW it's just not that.
How long did you have to wait for Cubie to arrive?