I wish I would have gone for the 32 gig. I had a 32 gig iPhone 5. Loved the extra space. Even if you don't need it it's always good to have.
Yeah I'm glad I was hesitant bout getting the 16gb and someone else got it before me. 32gb allows me to do more picture n video taking. My gf won't leave my 5s alone.
I know what you're going through. I debated this exact same thing before buying my wife her 5s. Since I knew she would likely be taking lots of photos and videos, I decided to get the 32GB. It may end up being overkill, but I like having the peace of mind that she should have plenty of storage.