I tried a 2nd blueray movie today, and it took almost 2.5 hours. Desktop PC has plenty of grunt, cpu is i7 2600K @5ghz with a 580GTX and 16gb dd3 memory, with 2x SSD drives raided + 2gb WD black series Data drive, so certainly not slow.
Normally standard dvd film rips take around 20mins depending on size & rip settings for a 2hr film and usually are about 1gb in size and look good on the iPad. Having now ripped 2 bluray films, although obviously image quality is better on the iPad3 I really don't think I shall be doing any more. I just don't think the extra quality achieved justifies the extra time to rip blurays and also the 3 or 4 times increase in file size.
If it's a film I intend to put on the iPad I'm tending more these days to check the films aspect ratio figures on the rear of the DVD boxes before buying, as the iPad is 4x3 aspect some of these modern day releases which are often on 2.40 aspect are really going to be difficult to convert without having large black bars top/bottom, yes you can open them up, or lose the aspect ratio in conversion to get something fuller. Standard widescreen 1.78 and old 4/3 films are obviously not a problem, but these 2.40 aspect releases do mean you'll likely have the bars top/bottom.