I have kept the ubuntu touch phone running (on Sony Xperia X) alongside my usual daily android with an old prepaid card in it for several months now (last post about it here). The pace of updates seems to have picked up and it really is looking good. Apparently OTA-13 will come out soon which will bring the operating system to a greater number of devices (link to ubports page here) and should develop the system further.
I am planning to give it another go with my daily SIM card soon and one thing that I felt was really important in everyday life was a functioning navigation app preferably with offline maps. Fortunately, the uNav app for ubuntu touch has been recently updated so I shall be getting that set up and tested before moving the SIM card over. Prerequisite for the use of offline maps for uNav is OSM scout server which is easily installed via the Openstore (app store for Ubuntu Touch), maps can be selected from the menu in local/bite-sized chunks so that not too much memory is used and finally, using UT Tweak tool, the osm scout server app can be set so that it keeps running in the background. All this is clearly detailed in the user instructions so should be no problem for all users who managed to get UT installed in the first place.
So I shall give it a test when the location service has found a few satellites and report back.