I don't know about you, but I really despise Word files. I hate dealing with them: they are bulky and slow, and full of potential problems. Even with Office 2008 for my Mac, they are a pain.
PDFs on my Mac are, however, pretty nice. As long as they can be loaded with the OS X's Preview application (99.9% of the time), they are snappy and quick to search. I have fallen back in love with PDFs on my Mac.
Why back in love? Well, in Windows, PDFs were a pain-in-the-ass. Acrobat was slow, would crash my browser, and just looked so unnatural. I understand there are alternative readers out there now (like Foxit) that solve some of these problems in Windows. In OS X, there's Preview. They aren't so bad anymore. I recall that someone once said that PDFs are the land mines of the WWW (due to the shouts of "Nooooo!!!!!" when you accidentally click one and have to load Acrobat).
So, a big "duh" moment came for me a few months ago when I realized that taking huge, complex documents that were written in Word (and some HTML documents) and printing them to PDF would save me so much hassle and pain. (For example, the 3GPP publishes all of their documents in Word.) I must say that it makes it so much easier to keep more of the documents open, easier to browse them, and I don't have to worry about accidentally modifying them while they are open.
Word 2008 is even nice enough to let you save directly to a PDF in the "Save As" dialog. This appears to be just a shortcut to OS X's built-in Print to PDF ability, but it saves a few clicks.
It's noteworthy that, for some documents, I might still have to open up things in Acrobat. My taxes, for example, have to be done with real Acrobat, since the text boxes were not created very well, and break in Preview. But with Acrobat 8 we have proper subpixel anti-aliasing on the fonts, and it's fairly snappy, so it doesn't bother me too much.
Acrobat 8 Reader on Windows, though, I've had a lot of trouble with. Specifically, WinShell (my LaTeX editor) will crash it constantly when it notifies it of an update to the PDF created by LaTeX.