I hope Microsoft delays the fix... so far, Word is BS, and even the Ribbon is a large, distracting strip of tabs. It's nothing but eye candy designed to appeal to the clueless.
Wtf it's normally only about 200MB, if not less. The *NIX version always seems to be larger than the Windows version.
The real problem with switching is more about VBA script and format compatibility issues.
Go-OO (a number of 3rd party patches to OpenOffice.org) is supposed to fix that:http://go-oo.org/discover/#vba-support