My work PC is a dual core lap top with 3GB of memory running XP Pro, it was nice to use with Office 2003 (aside from never being able to get consistent section numbering in a document). The company recently insisted in upgrading to Office 2007. The first install was botched up as they didn't remove Office 2003 before installing the new version, Windows Update then insisted on trying to update Office 2003 failing because it mostly wasn't there. You would really hope that by now a Microsoft installer would be able to cope with a simple upgrade. So I had them clean it up removing Office 2007 and 2003 completely and having Office 2007 installed again.
I was hopeful that some of the quirks that I had noticed, would be rectified by a clean install, but no unfortunately its not the case. It now takes over 15 seconds to start up Word, I watch as it paints the bottom part of the screen, then finally gets round to the top part of the screen. Apparently the Windows standard windows decorations are no longer suitable for mere word processing, it all has to be repainted in a non-standard way. 'Page no # of #' is no longer obtainable. All the menu items are moved or hidden, the ribbon eats up a big chunk of screen real-estate (always such a premium on a laptop), OK I know it can be minimised, but why should I have to care? Because I need to use a legacy format, opening documents now takes twice as long, and occasionally it suffers from typing lag. I've had my PC downgraded!
Back when a state of the art laptop had a P100 and ran Office 97, Office did everything I needed and more quickly. Once again Microsoft upgrade my working environment by making it go slower.
Office 2007 is the best reason I've yet seen to use Open Office, even loading the Java environment will not make it this slow. Google docs is looking attractive too.