I have the G Tablet. Picked it up for $279.99 when Woot had it awhile back. Out of the box, it's a very clunky experience. But once you root it and install a custom rom, it's amazing. Easily one of the most hacker-friendly tablets out there with top of the line hardware (it's packing a Tegra 2 dual-core processor). The viewing angles of the screen and weight put some people off, but neither are honestly as bad as many make them out to be.
I'm running 2.3 on mine, and it seriously flies. Great battery life too. Having the fullsize usb port on it for hooking up flash drives or external drives was a major selling point for me, and it's come in handy quite a bit. Once Google releases the sourcecode for 3.0, you can rest assured that the developer community will have it on the G Tablet.
I love mine, but you have to be willing to put the time into it. If you want something that works well out of the box without having to do anything major to it, the G Tablet is not for you. But if you enjoy tinkering around with stuff and want some top quality hardware for a low price, this is the tablet for you.