Also, it is much easier to combine content from many different TeX files than from Word/OO files, which makes it much easier to do things like compile lecture notes for a class or discussions notes for a project.
I view learning TeX as something like learning how to use vi or emacs. It's difficult, often painful, and hard to see the benefits in the beginning compared to †he big office suites you're used to, but once you get past the initial learning curve, you become remarkably more productive.