The InHaos Buono Uno R3 is very similar to the Arduino Uno R3, with a few small but significant changes. First, the power supply. It can be switched between 3.3V and 5V, and is capable of 1.8A output for powering greedy peripherals. Next is the low-pass filter on AVcc, which helps get stable and accurate readings from the analog inputs. There is a ground terminal that you can clip a lead to for test measurements. And finally, analog inputs A6 and A7 are on the board on a separate header location (header not included). The only problem we found with this board was the Vcc pad on that header being solder-filled.
The USB to serial converter is the Silicon Labs C8051F321 MCU, which is not similar at all to the ATmega16u2 on the Uno R3, and there have been issues with the firmware, which have apparently been sorted out. If you get a Buono Uno R3 that was manufactured before 2013/09/17, you will get the older firmware, and you will need to upgrade it.
There is a "Lite" version that does not have a USB converter. The difference can be seen in this picture.
|InHaos Buono R3|
|Operating Voltage||3.3 / 5|
|Test Current Draw|