I also have this problem. I have done everything recommended to optimize space. I have removed most photos. It's the System files that are eating half the space. Somewhere it was recommended to try a backup and restore via iTunes, but I'm unable to complete the restore because it says I don't have enough space on my MacBook. Similarly, on the MacBook, the System files are eating almost 340 gig of my 500. I've cleaned up everything I can think of... Something is not right here. The problem on the MacBook side is bigger and creating more roadblocks to production, but really they seem like the same thing on a different scale. What's up with this, Apple?