First, I have this board, and I am making a similar board using the CH340G chip as for right now. This chip is much better than the ft232r which the nano is using: 1, price; 2, size (it's sop16 vs SSOP-28) the uno is using an even smaller usb-ttl. The only problem is the Chinese made CH340G chip. It's very well-known chip in China, while it's an unknown elsewhere. The other con about the trace is simply not true. The thinnest traces are 5mil and is more than enough to carry 40 mA which the pins can supply. and thinner traces are even a good idea. Think about it, if you are not smart, and hook up the pins incorrectly, then you will burn out the traces instead of the 328 chip. those thin traces are mini fuses for every pins!!! micro-USB is actually better than mini. most cell phone these days uses it. There are reason about it, and not all about size. Google about it.
My conclusion: it's not a perfect board, but it's at least twice better than the original, and I am loving it. and ignorance is not good.
The real con: pins are not aligned (see photo). Quality control is the last thing those Chinese sellers case about; if you are using this uno board with a shield, think twice before buying this cheap board.
The real real con: the design of this uno board is simply dumb. it's too large and too old. it will works, but it's not very artistic design in my point of view.
Last but not least. I got mine directly from the manufacturer, at least that is what they called themselves, for 2 dollars USD/ 12 RMB; Cheap as in price, the overall quality of the board is great! If I am going to make these in thousands, I probably can't buy all the component on the board with 2 USD. These people are working very hard to earn few cents from making these board. Calling it cheapest is simply inappropriate in my humble opinion.
Last word: when choosing the board, pick NANO instead of UNO, because the it's using the same 32pins IC as the NANO. The UNO uses a 28 pins dip package. The extra A6, A7 on this board is just extra from the 32pins IC; It will probably won't work if the bootloader is burned as an UNO; In that case, you need to burn the Nano bootloader to this board via the ISCP board in order to use those 2 extra analog pins;
