A number of Linux distros have small footprints that make them especially suited to applications like running them from a USB stick. What accounts for the difference in size compared to the "full" sized distros? What is missing? Is it just that full-sized ones have bloat from being bundled with every conceivable driver and utility and tons of themes and skins, and with the small footprint ones you need to find and add the specific ones you need? Are they missing specific functionality, like the difference in Windows between the Home Premium version and the higher editions? If you want to use Linux as a Windows replacement OS, are there limitations with the small footprint versions that would require a full-sized distro?