1. full ripe Linux userspace unlike android
2. respect to gnu, unlike commercial android
3. not dumbed down by default unlike android (adblock possible over cellular (where it precisely needed due to ad suckage of expensive traffic), can remove Google forced chrome, can use libreoffice (with Google still ignoring ODF and sleeping with docx))
typing this from galaxy tab 3 2014, so that you know. Android is commercial baby toy, it's not gnu or Linux spirit, but it's a nice toy, unlike microsoft crap.