I've always backed up our iPhones and iPads on my iMac before doing iOS updates on them but never ran into glitches while updating until the last two. At least one of our four devices hung up during each of the updates and I ended up having to Google solutions and restore them from backups. Yesterday morning trying to update to 7.1.1 my iPhone hung on verifying software. I ended up having to do a long home button press and connect to iTunes. It restored fine eventually after several tries and an iMac reboot, but took so long restoring apps that I had to leave home without it. With millions of iDevices out there, there must be lots of folks who just click "update" and hope for the best.