So this question just popped out of my head on a not-so-busy day.
I have 523MB left out of the 16GB iPhone 6. That includes s h i t load of games that I never played. Now that is called, ladies and gentleman, optimised use of storage. You guys with lots of free space are wasting your money! Storage is meant to be used, not bragged as free space!
Get real, the price difference between 16GB and 64GB is a lot of money. You can buy 4 decent 64GB microSD cards with that!
I'm treating my phone as a backup camera -- i.e. I always backed up my photos as I do with my camera, resized them, and uploaded them to Google Drive for viewing with my other devices, including the non-apple ones. So, 523MB is a lot of space for taking picture with my phone. Also, I don't store my music in any of my iPhones as I found listening music using them made my ears bleed. I have a couple of DAPs perfectly usable for listening to my 7Digital lossless music, that is now using a 64GB microSD cards, with 3GB left each.