I was burning this movie the other day as well. You won't be able to get good quality on a single layered disc.
I had to use a dual layer disc to get a quality copy of this movie.
I took out the menu's, took of the end credits, and only kept ac 5.1 ch audio. It was still only burning at around 70%. To me 70% is unacceptable if you own a high quality surround sound system.
Do not look at percentages when you compress. Did you know that compressing Bewitched, Resident Evil Apocalypse, or Stealth to 99% will yeild you lower video quality than compressing Crash to 70%??
This is because Stealth and RE are at a lower bitrate than Crash. You will not notice any difference on your TV unless you are right up to your screen and you are looking very hard for the difference.
The thing is you have to use DVD Shrink (or Nero Recode). CloneDVD2 will not get you good results when you compress below 80%. With Shrink or Recode, as long as you get movie only with still menus (use MenuShrink for this) on a DVD5, you will have quality that is visually hard to distinguish from the original.
If you have DVD9s and do not mind using them, then by all means do this, just do not go out and buy them only to back up a certain movie that you are afraid of quality loss. Try it out on a DVD5 or a DVDRW first and see if you are pleased.
As for audio, do not worry about this. Audio is not compressed with CloneDVD2, DVD Shrink, or Recode. The only way to compress the audio is to Demux it, convert it to wav and then recompress it to a lower bitrate. Also, using Besweet to change it from 5.1 to 2.0 with 192 or lower bitrate will comrpess the audio. Software that changes the video format will compress audio though!!
