There's a very strange combination of contrary things about these boards.
According to the CPC website listing, the Kona328 is made in China, and they appear to have the hallmarks of a Chinese-designed and produced board - serif font on the silkscreen, generic unbranded parts, AMS1117 regulator. But on the other hand, it uses at ATmega8U2 for the USB interface (not something like a CH340G, like so many Chinese clones) and a resonator for the main AVR's oscillator (not a crystal, again like Chinese clones).
The datasheet appears to have been written by an American, or for a US audience, as it uses US-English spelling (e.g. "center") and terminology (e.g. "wall-wart") and describes the board's dimensions in inches only.
The fact it uses an ATmega8U2 is also slightly strange. Why not a 16U2 like the current Arduino Uno R3? I'm not sure of the reason why Arduino boards moved to the 16U2, but you'd expect a clone to be the same. Unless they're using an older firmware revision that still fits on an 8U2. Also, I wonder whose USB VID/PID they use, as Arduino boards have their own, rather than use the LUFA ones.
And the final thing is, they're not even particularly cheap. CPC have the Kona328 priced at £13.19 inc. VAT. About £10 less than an Arduino board, but still at least 2-4 times the price of a clone.
I don't see anything about these boards that makes them any better than a $5 Chinese clone.