Oh, I don't know, DVD-RB does pretty well without me messing with it. This is interesting, though, and not really off topic. We're talking bitrates, the higher the better. Between 6 Mbps and 9 Mbps, you don't need to worry, below that you MAY begin to see compression artifacts. Go much below 4Mbps and you'll start to have some, alright. Artifacts not related to compression can be poor encoding or display problems. For example, if your TV has sharpness set too high, well, that's a mistake.
According to my bitrate calculator, a 2 hour movie with a 224 kbits/s audio track can be done at an average bitrate of 4,853. (Or 4.853 Mbps). This is on the basis of 4480 MB available and 92 MB overhead, 196 MB for audio. So you can see why some folks just reauthor with one audio track. If you have a really big TV, it pays to compress the least amount possible.
TitlesetBlanker and VobBlanker are popular freeware apps for discarding extra stuff and unwanted audio tracks without buggering the menu. Naturally, this can improve available bitrate, sometimes a great deal.
Uh, JMHO and all that. Feel free to disagree.