I tried a DFU restore, for the heck of it to IOS 9.0.1 from 9.0.2 after doing a full backup. After I restored to 9.0.1 and tried to restore my backup, itunes churned away for about 30 minutes only to say at the end the back-up was "corrupt". Suffice it to say I couldn't believe it as I had no other backup and thought I lost a vacations worth of photos from my camera roll. I'm not sure how, but after about 3 hours and a DFU restore back to 9.0.2 the restore worked. However, I lost a few years of "my life" in the process.
Suffice it to say a word to the wise. Plan for the unexpected and if you have any irreplaceable photos, back them up separately.