The maximum bitrate for AC3 is 448 kbit/sec.

I disagree that AC3 is unacceptable for new transfers. Even though AC3 is compressed (and lossy), how many commercial DVDs come with PCM audio? Most commercial DVD are AC3 or DTS, even music ones.

He says that you want to encode your video at 9000 kbit/sec. Well if you use PCM audio then your total bitrate is 10536 kbit/sec which exceeds the DVD spec.

There's no one correct answer for all situations, you can make a case for both AC3 or PCM depending on your source audio.

For example if your encoding a satellite or cable television broadcast, then the audio has most likely already been compressed via a lossy codec. If you convert it to PCM, you still have a lossy source. But on the other hand if you encode it to AC3 you're introducing another level of compression. Tough call.

If you are encoding audio that has come from an in-camera mic then the audio quality isn't going to be optimal so PCM may be overkill. In this instance I would suggest using AC3 @ 448kbit/sec.

If you have a separate audio source (ie. a recording from a DAT deck, Microtrack, Edirol R-1) and you want to preserve the high quality recording, then you would have a very strong case to use PCM.

I guess you need to decide what is more important with your DVD and who it is aimed at. If you're authoring a DMB, Grateful Dead or Phish concert then your audience is probably biased towards the audio side so they would lean towards PCM audio.

Finally, I guess what you need to ask yourself is: Am I happy with video encoded at 8300 kbit/sec ? If you are (and don't mind only having 1 hour per DVD5 disc) then go with PCM. If you'd rather use extra bitrate on the video or add more than 60 minutes per disc then maybe AC3 is for you...

Hope this helps