Hi Ray, thanks for the info...
I am only interested in fitting a movie onto a single sided DVD, so that's OK.
I use DVD Shrink... simple and quick for re-authoring / compressing.
I squeezed the 25GB Transformers 2 main title down to 4.7GB by:-
1. AnyDVD HD Rip to PC's Hard Disc
2. Convert Hard Disc mts2 main title using "BestHDSoft Blu-ray DVD Ripper" => 9GB DVD format
3. Compressing 9GB DVD format using DVD Shrink to 4.7GB
The results were good as a first stab even though "BestHDSoft Blu-ray DVD Ripper" had a demo message running though it!
Yep, and when i have more time to explore this I will

Thanks again Ray, Mark