I'm talking about the High and Medium quality encode sets that you obtain when you press CONTROL+E on DVDit 6 pro.

I read on this page: http://www.videohelp.com/dvd
the average Bitrage for DVDs is 5000 but DVDit have the encode set for High quality at 8000 and medium at 6000kbps. So are the standard recommendations for DVD set to low image quality? and why? and if that is so... then why on the same page it states the quality is excellent when using around 5000kbps?