this is going to sound quite bolshie but I honestly can't see how you can say a DVD5 version looks the same as a DVD9 version when you are using a PCM soundtrack.
if you've put the original PCM capture audio track on a DVD5, that means you are giving up around 1.2-1.3GB of disc space to the audio. that's a 3rd of the discs capacity which means you have around a 3GB M2v encode file.
on a DVD9 you've got about 8GB useable, something must be up if you've encoded a DVD9 version and it looks no better than a DVD5 encode. seriously
unless you are using a DVD9 DL disc, admirable as it is to retain the original PCM file, you are giving up a lot of space on a DVD5 single layer disc to sound and not picture. parituclarly when you can get a 300mb ac3 file instead.