What about "Professional Quality"?
Here's what Macword says about this feature...
Professional Quality encoding
iDVD still retains a two-hour limit to how much media you can put onto a standard single-sized DVD, but now iDVD 08 provides another encoding option: Professional Quality.
The Pro setting uses two-pass variable bit rate (VBR) encoding, which means that iDVD examines every frame of video twice to determine the best amount of compression to apply; the High Quality setting uses single-pass VBR. The Pro setting takes more time, of course. I burned a two-hour project in 3 hours 52 minutes on a new 20-inch iMac; at High Quality, the encoding and burning took 1 hour 15 minutes.
In my testing, video encoded at the Pro setting benefited most in terms of color quality. The high quality version appeared slightly washed out in comparison. The Pro encoding also enhanced the appearance of still photos in slideshows. Speaking of slideshows, you can now add movies to them, letting you punch up photo essays with a little motion.