Got one of these little boxes. It's not a Linux box but it does CCcam and Newcamd so is suitable for server use. I have found the pictures to be very stable even on HD channels, and far better than the DM800 clones. Latest firmware allows this to stream divx and MKV's from the PC in HD, although the version I tried doesn't have the cams as it's in beta testing.
All in all a very good little receiver, and at £130.00 - £140.00 a good price for stable HD reception.