The best use I found for MultiView was as a helper app inside my DiskMaster setup.
Basically, MultiView's strength is that it will do something mostly appropriate at just about ANY file you throw at it. It's great for a "good enough" preview or look at any file.
(It's weakness is that usually it isn't the best at ANY of those things, though!)
So, what I did, was put a "Preview" option in DiskMaster (or DirOpus, or whatever your flavor of file maanger), and then you configure that button to use multiview on whatever file(s) are selected. So, you can pick three files of different types (say an audio, a video, and a text), and quickly get the contents of each displayed in an appropriate way, without having to worry about picking an appropriate app for each, or whatever... "It just works." (Provided you have the appropriate datatypes installed, and are running OS3.x)