Setting aside the fact that LaTeX will perform typesetting, those word processing tools utterly fail for creation of documents with lots of (or complex) equations.
They are also very cumbersome for generating cross-references, bibliographic formatting, and management of figures/tables.
One killer feature MS Word *does* have over TeX-based solutions for now is excellent commenting, change tracking and shared collaboration features.
I know both worlds well, having used MS Word for collaborative proposal writing, and TeX for scientific publishing. I strongly prefer LaTeX.