I started with the 16 gb iPhone 6, but quickly started having to manage my storage. I underestimated how much I would use and was not enjoying my first iPhone experience at all. Now I have a 64 gb 6s and feel like I have plenty of breathing room. I have used just under 18 gb, most of it being music. My dh, on the other hand, is a very light user and is happy with 16 gb. He has very few apps, takes virtually no photos, and streams all of his music. Some people are capable of making it work, but I am not one of them.