The hardkernel team hit it out of the park with the U3. Better specs than the U2, better form factor, and CHEAPER than the U2. You don't see that much nowadays

The hardkernel team hit it out of the park with the U3. Better specs than the U2, better form factor, and CHEAPER than the U2. You don't see that much nowadays. The processing power alone is significant, compared to the other options on the market, and they've added support for GPIO to the U3.