I’ve used Sailfish OS on the original Jolla for a little more than two years from April 2015 through July 2017. Last month, I was finally fed up enough with the horribly slow and limited hardware (couldn’t play music and open OsmAND at the same time) and got a OnePlus 3T with LineageOS.

Tidbits of my personal opinion:

- SailfishOS is much more unixy - getting a shell, setting up a SSH server and syncing files with rsync was no problem at all. I have not yet understood the directory structure of LineageOS

- The permission of apps was a problem, but not more so than on my laptop. Ideally one could solve this by only installing trusted apps, but this was unfortunately not an option (Whatsapp)

- The native e-mail client actually knew about e-mail. On LineageOS, I had to install K9mail to get such simple things as proper treatment of signatures delimited by '-- '

- The user interface on Sailfish was much more usable, in particular the swipe gestures to quickly close apps as well as the tiled view from which you can directly interact with open and running apps. Feels more like a proper computer instead of a single-threaded/single-application-at-a-time thing.

- I actually trusted the team at Jolla with providing decent updates etc. With LineageOS, I am using some unofficial ROM provided by a random guy on a largely random forum which may or may not work with over-the-air updates (it’s claimed to work but I haven’t tried it yet). I definitely trust my phone less now than I did before.

- The hardware is of course much better on the OnePlus -- had Jolla/Sailfish sold something equally good or even only slightly worse, I would have bought that again.