First things first. The installation of Microsoft Office Home and Student, according to its product page, requires about 3 GB of hard-drive space, so downloading will take some time. Conversely, the DMG file for LibreOffice 4.0 for Mac OS X is about 165 MB in size, and downloaded in just a few minutes. Once expanded, the single LibreOffice executable file occupies 545 MB. Office for Mac 2011 consists of more than 14,000 files and occupies 1.35 GB of hard-drive space.
For those that do decide to take LibreOffice for a spin, be sure to read the release notes for some important installation guidelines, particularly when running it on Linux.