Nice find.... Worth it in my opinion...
Well, it turned up, delivered from Amazon around mid-day and I'm pleasantly surprised. The price seems to be around the same as other sellers advertising on Amazon, who are quoting expected stock late October.
I've seen a few unboxing videos and some of the units have turned up with an empty MicroSD card slot. Mine arrived with a 32GB card in the external slot. Removing this doesn't stop the RG350 from booting. The OS is held on an internal MicroSD.
Pretty sure you can guess what's on the card in the external slot?
It seems to run the demo of Quake2 at a reasonable rate, though I've yet to play-test it.