Mmh when I compare my BQ 4.5 with my Jolla and Ubuntu Touch with SailfishOS I want to keep the BQ with SailfishOS ;-)

Ubuntu Touch is far from being a finished product and unusable as a daily driver - the email app is only checking for new mail while opened (and not even then reliable) the GPS fails regularly when wifi is activated, the calendar is even more basic then the sailfish one and if you don't use google mail (you might think that most people who are opting for an alternative OS don't ) CalDAV and CardDAV are only supported via syncevolution and the terminal - etc etc

Don't get me wrong - fingers crossed for the evolution of Ubuntu Touch (not the unfortunate way of FFOS) we need more alternatives on mobile devices but it's still a long way to go (but nevertheless fun to play with ;-) ) and if you are looking for an OS that runs you through a working day SailfishOS is imho the far better option