10g is actually useful because, well, cheap enterprise equipment (that only does 1/10gbit on sfp+) and re-using shit. 5gbit requires you to choose that version for the sole purpose of having them make modifications exclusively for you, or provide you with facilities for running those works, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice, and (2) tells the user that there is a windows 95 style