I love OO, but...
I use Open Office on my Mac and Linux machines, and I really like it. But working at a very large Fortune 20 company (about as large as they come), we often have to fill out these large XL spreadsheets with lots of programming in the sheet. I wonder how well these translate to Open Office?
That said, I see less and less of these very ugly and kludgey XL sheets. I hate them -- they're buggy as hell. Most of this stuff is moving to the web, so it's probably a concern that is past it's time, except at a very large, latent corporation.
Also, Open Office, being open source, seems to have a lot more options for customizing the word processor or spreadsheet. With MS Office you have VBA and I guess .NET to extend and expand Office, but it's a black box. I checked out, say, how to add a custom menu item to Open Office Writer, and it's not that hard. It's all written in Objective C, like Mac OS X apps.
It's funny, but Mac OS X is so *nix... If you like *nix but also like mainstream apps and not fudging around too much AND you don't mind spending $1000+ for a decent machine, I would suggest getting a Mac.
My Mac is for personal use, but I am doing MySQL and Spring/Hibernate/JavaEE stuff on it, and I would say, for the Java software developer, Linux and Mac OS X are the best options. But with a Mac, you can develop iPhone apps (good luck getting them sold on the store -- one of my friends just got rejected and is pissed off).
But yeah, to me, Windows is a joke. Yeah, I know everyone uses Windows and they have a huge market share. What does that say but it's mediocre... People buy it because it's cheap and you can get a $300 laptop at Costco, and corps can get something even cheaper. Windows has the right mix of being cheap, good enough, and being familiar with most people.