I find that in rare cases I need to bring my old smart phone with me (traveling, mainly) for things like airline tickets, movies on planes, maps in new areas.
Otherwise day-to-day I am exclusively using the XP3. My screen time is now at an average of <10 min per day, and my battery life is between 5-6 days on average.
Super happy with the experience, and I bought back so much more time and sanity by not staring at my phone for hours per day.