The other big downside is that if you intend to run Linux on it, the graphics driver is limited to 16-bit color depth. The OpenGL ES implementation is also shit - I wrote a simple program that renders a textured quad full screen and it only gets 80 FPS with X using 90% of one CPU.
I asked about it in the forum and they are aware of the problem, but they don't have a lot of resources to fix it. They state there's a bug that's causing the frame to be rendered 4x more than it should be. Pretty big bug if you ask me!