Maps on a phone app will be easier than my Garmin 510. I only use maps for big rides, like unsupported centuries. I like the Garmin for my typical riding since I'm looking for data, like time and distance info. I also like the Garmin since I have 5 bikes and I have a mount on all of my bikes. Lastly, for the long rides, my phone battery will not hold up all day.

So if you have one bike and don't do a lot of day-long rides, find a good phone mount. I will let someone else identify a good phone mount.