Well anyone should know, but most of my colleagues in grad school didn't, so I thought it would be usefull to point out
I see problems with Word, for example I was unable then to set my own size and offset of super and supscripts (which is annoying when they are too small), also the fact that it reformated positions of pictures randomly and many many formating settings are just much easier to set in Open Office. Also, then OO had simple button to save as PDF, while you needed virtual printer to do that in Word. Now many things changed to better for Word, but also they screwed up the UI unbelievely, so it would take me more time to actually find anything in Word now.
Also, only when working with OO, I learned that Help is something that really helps you, which is an experience I lacked in most MS programs. I'm also used to certain keyboard shortcuts, in some new versions of Word they just changed them, changing them in Writer is just absolutely easy, but it took me more than half an hour to google it up for Word.
And for the last thing it's true that TeX is more neccessary for complex text works, but it also provides more advanced typographic features, which is something not many people know about, or care about, but it doesn't mean it's useless, even if only for a poem you send to your granny
This is the reason why many swear to TeX or other DTP programs. Those who know typography, know the difference. (I don't, that much.. I'm just starting to be horrified by the amount of things that can be wrong there)