I'd still be happy with MS Word 5.1a that I used waaaay back when. As for OpenOffice, I haven't tried it. I have tried StarOffice for a while (it's predecessor) and it was pretty slow. Since the package still runs on Java, I can't imagine it being quite as fast as MS Office (I can't believe I said that).
On a side note... More most typing I use gmail or notepad. I use Excel for one spreadsheet, and I rarely use the other things. Sure, if I had to pay for MS Office it would be a different story, but I get site license.