In addition to having their own server issues, the iOS 7 download demand caused wi-fi issues on several college campuses. According to Business Insider, affected universities included New York University and Ohio University, who urged students to delay downloading the iOS upgrade.
Almost immediately, a vulnerability (aka bug) was discovered which allows someone to bypass the lock screen to photos with the ability to post them on social networks, such as Facebook and Twitter. Of course, Apple says that they are working on a fix.
My personal experience was not without issues. iTunes kept telling me that I had to download version 11.0.5, which was the version I was already using. I had to find the really newest version (11.1) of iTunes on Apple’s download page. Once I downloaded and installed it, I was ready to update my iPad. For a while, it kept telling me that my iOS version (6.1.3) was up to date. Eventually, it figured out it wasn’t the latest version and eventually downloaded iOS 7. I chalk that up to server availability (or unavailability). Once it could connect to the server to find out that there was a newer version, I was good to go.