Apparently this is a major release.
They got rid of a lot of legacy code from OpenOffice that was either inefficient and/or redundant. It does seem a bit faster and more responsive than OO. (In Windows)
Plus they added the ability to annotate text documents (Should be useful for collaborative writers), and added a remote control app for Android users for their Presentation module.
They also rewrote the User interface, it doesn't look all THAT different to me, but they claim improved accessibility and sizable dialogs.
For linux users they also promise tighter integration with Unbutu Unity.
It is also available in a form to load on a thumb drive - see portableapps.com
http://www.pcworld.com/article/20276...ffice-4-0.html
I've downloaded it, and I will be keeping it. It IS faster and more responsive. I'd say it is a good to excellent FREE replacement for MS Office.