I ordered one on the first day they showed stock on hand and it arrived here in Calif in 12 days, packaged well. My first impression was this thing is tiny and thin compared to my 9 pin serial Arduino board. Even with the additional I/O pins avalible, the footprint outline of the board is that of a standard Arduino.
It has four manual switches on the board, a push button for the reset function, and 3 slider two position switches that select 1. 3.3v or 5v operation, 2. power from usb or external, 3. Auto DTR reset on or off. It also has very small LED indicatiors for power on, reset, transmit and receive data on serial port 0 and a pin 13 led. These are very small and hard to see until they light up.
It uses very small connectors for both external power and the USB.
I downloaded Arduino version 16 (I had only used up to 13 till now) and everything worked first try, was able to upload sketches with no problems.
All in all my first impressions are very good, this is a lot of board for $50. If anyone has any questions that I can answer, let me know. Got to run for dinner.