I am using this adapter to program and talk to Moteinos via USB serial. It works great. The voltage selection switch is nice although I have not had a need to change it from its default setting.
A minor "by-design" issue that I ran into is that one should not leave the adapter connected to a target device (like the Moteino) if the device is in-service and powered by a separate source -- in that case there will be a voltage conflict on the Vout pin of the adapter (the adapter puts its own voltage on this pin, and the target also puts a voltage, which most likely will be different, on the same pin). To avoid this problem and so one could leave the adapter connected while the target is in-service it would be nice if the adapter had a jumper or switch so one can manually kill power on the Vout pin. There are other solutions, like bending the Vout pin, or creating a small adapter that leaves out the Vout pin, so this is not a major problem.
The pins of the manually soldered female header were left too long on the other side of the PCB, causing the pins to interfere with my circuit. I trimmed them myself but it'd be good if the maker ships the adapter with the pins already trimmed.
Overall, I think that this is a good product and at a good price. I am happy I bought it.
