I've re-encoded Lord of The Rings "Return of The King" and used 3 pass (1 vaf + 2)
The results were excellent given the amount of compression involved. More passes won't give you jaw-dropping better results, it'll just take longer.

The average bitrate used along with the reduction percentage is reported after you do the prepare phase in Rebuilder. It doesn't take long for the prepare phase.

As for skipping and stuttering playback try this test:

1. take a note of the chapters and scenes where you experience stuttering playback
2. extract the original disc to hard disk (you should have this already)
3. run VobBlanker to remove all content except the affected chapters; the content you keep should be small enough to fit on a DVD-R blank so won't need re-encoding
4. burn the content to a DVD-R for testing
5. play this disc in your standalone to see if the problems remain

You can read more about my problem with Shawshank here.

Regards

TZ