www.makemkv.com

I started doing the Monsters University DVD and I've been doing it for 1 hour 30 so far and it says this in the bottom bit (new stuff is kept being added)

Complex multiplex encountered - 49 cells and 5461 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Angle #2 was added for title #55
Complex multiplex encountered - 49 cells and 5454 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Angle #3 was added for title #55
Complex multiplex encountered - 49 cells and 5468 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Title #56 was added (154 cell(s), 1:38:27)
Complex multiplex encountered - 49 cells and 5461 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Angle #2 was added for title #56
Complex multiplex encountered - 49 cells and 5454 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Angle #3 was added for title #56
Complex multiplex encountered - 49 cells and 5468 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Title #57 was added (154 cell(s), 1:38:40)
Complex multiplex encountered - 49 cells and 5461 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.
Angle #2 was added for title #57
Complex multiplex encountered - 49 cells and 5454 VOBUs have to be scanned. This may take some time, please be patient - it can't be avoided.


Stuff like this? Is this what its meant to do?

Yes, sometimes the directory structure of the DVD gets complicated, as a way of "protecting" the disk. Although I don't remember having a disk take 90 minutes or more, I have had them take 30-60 minutes to get through analyzing the structure, once the "Complex multiplex" warning comes up.