When I got my iPhone 6s with 128GB I thought I'd finally have the space to have all my photos and music on device. Which I did to start with.

Sadly my total photos/videos in iCloud is now up to 43GB, add that to the 43GB of music and other assorted stuff and I'm out of space. So I had to turn on the iCloud Photos "optimize storage space" option on a few months ago

So, looks like I "need" a 256GB iPhone...

I wish Apple would use the space more intelligently with "optimize storage space" turned on. At the moment there is 20GB of free space on my phone, it would be nice if they did something like always keep the full size images from the last couple of months on my phone if there were space.