I have run Word, Excel and PowerPoint through wine. They all operated relatively well (some keystroke functions just don't work, and I am a keyboard driver). Visio did not behave well at all.
I use OpenOffice, unless I am working with one specific client, who does some weird image processing in Word (OpenOffice hangs in an infinite loop). If I go into Word and remove a couple of the images that are in their default document template, everything is fine.
For that Client, I bought VMWare and run the copy of Windows that came with my computer in a virtual machine. But I wouldn't dream of doing that on a machine with less than 256M of RAM, and I don't do it on one with less than 512M.
I understand that Applixware (spelling?) is very good at running MS products under Linux, but I've never used it myself.
pansophic