Just received my G7 yesterday. It's a replacement from Willgoo for My JXD 7800 which died under their warranty period. Willgoo literally opens the box and wraps the unit in bubble wrap before shipping. They may even give it a test spin before wrapping.
So far, I like it. Even though the screen is pretty much crap next to the 7800. It reminds me of my old Sega Nomad screen - hard to find a decent viewing angle, blacks are blue-tinged. Obviously it IS better than an ancient Nomad screen, but it's definitely a place where GPD decided to save some cash...
I installed the most current rom update (android 4.4 - v 1.01) via PC - all went well. I've noticed that, like the 7800, the 1.8Ghz Cortex A9 spec is now bogus. Mine clocks at 1.4, just like my JXD, which was a second-gen unit.
Still playing PSone at full speed. That's just fine by me...