As a counter-point, I bought a Nexus S (4.3") when they were first available, I loved it and appreciated the screen size bump from my older Nexus One. But when my employer gave me a Galaxy Nexus (4.7"), I thought the screen was too large. I can still use the phone, but a lot of one-handed uses feel awkward or strained because my thumb can't reach the top of the phone without having to first reposition the phone in my hand. When I go back to my Nexus S, I miss the size and clarity of the larger screen, but I love having the smaller and lighter device in my hand, and it's so much easier to use.
While I still prefer the Android OS, I think Apple has struck a good balance in the iPhone 5 by making the screen larger and a proper widescreen resolution (I love being able to watch Netflix fullscreen on my GNex), and the hardware design looks amazingly good. I just wish I could run Android on it instead of iOS.
Nexus S had a 4-inch screen (but it had an aspect ratio of 5:3 not 16:9, which means it had a noticeably larger screen than the iPhone 5).
This is a good opportunity to remember that we measure screen size by the diagonal. Which might be misleading if you are comparing screens of different aspect ratios. Most people seem to think Android tablets have a larger screen than the iPad (10.1 vs 9.8 inch), while the iPad has a larger screen because it's 4:3.
I needed to get another phone weeks before yesterday's iPhone announcement, so I went with the Galaxy Nexus, since it is contract-free and affordable.
Attempting to select multiple emails, one-handed across the screen with my thumb, has lead me to drop the phone several times.
Fortunately it is built like a cheap plastic tank. Dropping it is part of how I introduce it to people. "Remember when you used to drop your phone and the back and battery would go flying off, but the phone would be fine?" CLUNK
I prefer Android because it allows apps to do more things for the user, and allows them to better integrate with the system as a whole.
I can replace the on screen keyboard with one that has a full five-row keyboard for times when I SSH into a machine. On a similar vein, when I SSH into a machine, I can actually leave the SSH session running in the background while I switch to another app, without fearing that the OS is about to kill my SSH app while I'm looking something up or responding to a text message. I can also leave my IRC client running in the background without it constantly needing to reconnect when I switch back to it.
Intents in Android, especially in combination with the global Share mechanism, allow any app to receive arbitrary data from any other app, meaning apps don't need to know about specific apps or services in order to integrate with them. Clicking on a URL allows you to choose which browser (or set a default) to open the link in, allowing you to use alternate browsers (or alternate email clients, SMS apps, dialers, etc); tapping Share in the browser allows you to send the current URL to any application that can receive a URL, making apps like Instapaper, Pinboard, and 3rd party Twitter clients have the same capabilities as first party applications.
Sideloading apps means I'm not limited to installing programs from the Android Market/Play Store, and can do things like buy apps directly from the Humble Indie Bundle and install them on my own.
Proper background service support, and allowing apps to affect things outside their sandbox, lets me run programs like Locale [1] that can monitor the phone's status, location, etc, and modify the phone's settings automatically based on a set of conditions that I've pre-arranged. My phone automatically silences itself at night time and while I'm physically at work, turns on my Wifi when I'm at home or work while defaulting it off when I'm out and about, and more.
That's just some of the reasons I like Android better than iOS.
While I still prefer the Android OS, I think Apple has struck a good balance in the iPhone 5 by making the screen larger and a proper widescreen resolution (I love being able to watch Netflix fullscreen on my GNex), and the hardware design looks amazingly good. I just wish I could run Android on it instead of iOS.