I got a Viewsonic Gtablet as a birthday present a few weeks ago with the intention of hacking it with custom ROMs and getting Android Honeycomb on it. It is a good tablet being that the hardware specs are very similar to the Motorola Xoom at half the cost (seen as low as $275 new). The only downside to it is that the default Android 2.2 build that is on it sucks to say the least. Many 2.2 and 2.3 ROMs are available on XDA and Slatedroid to fit your needs.
The only real downside to the Gtablet is the bad viewing angles on the screen but this does not bother me too much since I am not using it to watch movies with others or something that would require more than just me looking at it.
I have finally got Honeycomb on it and am happy with it even though it is an Alpha release since it is a hacked ROM being that Google is not releasing the source for Honeycomb. So aside from a few bugs it is great. You can also over-clock the CPU to around 1.5Ghz with no real impact in terms of overheating using CPU Master. Once you over-clock the tablet screams compared to a Xoom.