I don't use minimaps either, but I guess their utility much depends on what kind of documents you're editing. For programming languages where code is mostly structured inside functions, the "structure" view listing the types and functions in the file seems much more useful, as well as quick-search based on name and similar features.

But if the content is, say, HTML, or LaTeX, or a Word document, then I can see a visual representation being more useful. It would be interesting to know if there's some correlation between people liking/disliking minimaps and the type of content they tend to view/edit.