These boards use an original ATMEGA328 chip and are 100% compatible with the original Arduino Nano.
The main difference is the use of a CH340 chip for USB instead of FTDI, which means older computers might not recognise the chip. But we have tested it successfully on Windows 7, and Ubuntu, and have found no issues. CH340 is actually an improvement though.
They're what we use to control our WS2812B strips. They use Mini-USB cables, which we'll have in stock soon.