For the love of god, please don't make the same mistake I did by switching to the iPhone. It doesn’t “just work,” and when it does, it works poorly.

Where iOS lags the Competition

There are no separate volume controls. You are only able to adjust the volume if your
volume for that particular function is activated. For example, you can only adjust app volume from within an app, you can only adjust ringer volume when not in an app, and you can also only adjust headphone volume when headphones are plugged in. I can't even tell you how many times I've hurt my ears because I previously had my phone plugged into a stereo with volume on max and, unable to adjust headphone volume in the interim, blew up my ears when I started listing to music through headphones.

You can only toggle your phone between 2 ring settings (e.g., ringer or silent, ringer or vibrate, silent or vibrate). You should be able to toggle through all three.

You have to download and/or activate separate keyboards for things like a swipe feature or emoticons. This is inefficient. For example, Windows Phone has these 2 features built right into the stock keyboard.

The keyboard doesn't toggle between lower case and upper case letter so it's hard to quickly tell when you have caps lock on. Often times my thumb falls in the way of the caps lock button so I need to move it away to see. I cannot believe the keyboard is unable to toggle. It's the only keyboard I've ever seen that doesn't do this.

The keyboard only suggests 2-3 words (far less than the competition) when you're typing and the suggestions are terrible.

If you type a word incorrectly a few times, it automatically adds it your keyboard dictionary (even though you didn’t ask it to!) and you need to reset your dictionary to fix the problem, since it keeps autocorrecting to a non-existent word. I have to reset my keyboard about once every 2 weeks because the keyboard on the iPhone is so terrible that I often mistype words, and before I know it, they’re added to my dictionary.

If you have no cellular connection or you’re in airplane mode, every time you open any app that uses cellular connection or data, the phone interrupts what you're doing with a pop-up notification to inform you that you don't have a connection. I’m not an idiot, I know I don’t have a data connection, I have the damn phone on airplane mode! There's no way to turn off these
notifications. Ridiculous.

Notifications are separate from what occurs on your phone. For example, if you get an email notification and then step into an area that has no service, when you open your email app, the email isn't there because the phone doesn't cache the emails. It makes working on my subway commute extremely unproductive.

You're unable to set a proper Out-of-Office message in Outlook. You can only set an "internal" message, which is basically useless. You are unable to set both an internal and external message.

The crop tool built into the phone doesn’t actually crop pictures, so when you transfer these so-called “cropped” pictures to your computer, they are no longer cropped. One must use a 3rd party app, such as Photoshop, to truly crop pictures.

Glitches with iOS

Often times when I unlock the phone, the screen orientation is stuck in landscape mode and I need to re-lock and unlock the phone to fix it.