You do have to do a full restore if the update puts you in a recovery loop, like it did for me!! You can use tiny umbrella to get you out of recovery mode but not a recovery loop! The only way to get out of a recovery loop is by puttin your iPhone into DFU mode and doing a full restore!
How to put your iPhone into DFU mode:
1- Connect to iTunes
2- Hold down your power and home button together for ten seconds
3- release the power button but keep holding down the home button until you see a notification pop up I. iTunes that says it has detected an iPhone in recovery mode than you can let go of the home button!
4- Then you just have to click on restore and let it go!
You may have to do this more than once but it worked for my iPhone 5S!