Graphics' main problem is that it only supports 8-bit color, which is no good for Aqua. On the upside, it does seem lossless, the color conversion notwithstanding.
And like Animation's 8-bit mode, it only has two quality settings, though they are arranged slightly differently: >medium and ≤medium.
Apple's QuickTime Compression and Decompression Guide has a description of the Graphics codec. MultimediaWiki has technical information about the Graphics codec.
