I just backed up Braveheart (174 minutes) to my HD using DVD Shrink with deep analysis. What is the likely quality going to be if I put it on 1 DVD? Anybody get a longer movie to 1 DVD using DVD Shrink? How was video quality?

Well I used DVDXCopy Xpress to backup Braveheart with an excellent result (cringe). With DVD Shrink you can see how much the compression is. Generally anything less than about 35% is fine for me. Make sure you re-author and untick things like unwanted extra subtitles (sub picture) and extra audio - you only need one audio option. By doing this you only compress by the minimal amount.

I cant remember the longest film I've done but for example Gladiator - 155mins after all extras,menu,not needed subs & audio were extracted came out great (but that was with DVD2One 1.13)
Oriphus will no doubt let you know soon about quality of DVD Shrink in deep analysis on long movies as he has tested enormously 2.3 & 3 beta 5

LOTR 2 towers, about 180 mins. Didnt even use deep analysis and it looks perfect.

I agree The 'Two Towers' is amazingly good considering it's compressed by nearly 45%.

I too backed up LOTR 2 Towers and it turned out great! At 45% compressed, the quality was good, DVD Shrink is an excellent program! :)

Does the deep analysis function help? It doubles the processing time, but if it helps it would be worth it. If it doesn't help...

I copied the Godfather it looks ok used DVDShrink 2.3 no deep analysis on 2.3.

Deep analysis does improve video quility, I found that using DVDShrink I would little white spots once and awhile on the screen but the deep analysis takes the white spots away.