Also, of all the people I know that have iPhones, a surprising number of them had their devices bricked by iOS 7 in such a way that even restoring in iTunes would not fix it and they had to resort to some quite nerdy solutions. Not very user-friendly eh!
I do wish Apple made it easy to just "format and reinstall" an iOS device. Why does it have to be so ridiculously complicated to do this?? If an installation goes wrong, there's literally nothing you can do in many cases because the device refuses to accept any incoming connection.
Also, I've learnt the hard way that installing a new version of iOS means that your device will likely be much, much more sluggish to do even the most basic tasks if your iPhone is soooo old that it's been out for more than 6 months. If that happens, too bad, you can't downgrade, because **** you, that's why. It's Apple's way of saying "buy a new iPhone every year or else we'll make sure your current one breaks".
So unless I had an iPhone 5 or newer, I would not install iOS 7. I'd rather have an old OS that works well than a new OS that doesn't work.