You could try
Fairmount, which works with VLC to mount an unencrypted image of the DVD which can be used by any application. So once Fairmount does its thing, you can just copy the data to your HD in the Finder.
There's also an old app called
OSEx. I've never used it personally, but it has some good (and recent) reviews on MacUpdate, so I guess it still works.
I've never done speed comparisons, but Fairmount has works with discs MTR and Handbrake both crashed on.