It will take these items to get me to go full android or even windows mobile. I am so hooked into this ecosystem, there just isn't this cohesive ecosystem offered on android nor windows.
Missing features:
* imessaging. Send 100MB images, videos, contacts, nearly anything encrypted. Built in no configurations needed. Works with my OS X between my wife's iPhone, my iPads, and iPods.
* icloud sync: emails, notes, reminders, bookmarks, calendars, photos, apps, all between my Mac OS X and iOS devices
* photo stream. The most useful feature ever
* iTunes/iBooks: easily drag and drop or sync everything effortlessly. Includes metadata to organize all media
* AirPlay. The best wireless feature bar none. I can stream from my Mac OS X or iOS device to my atv effortlessly and works 99.9% of the time. No hassles at all
* FaceTime. No 3rd party app needed. Works 100% of the time and has no competition. At least quality wise.
* Unicode support and handwriting has no equal. No other platform does this as superbly as iOS.
* battery life. Best thing compared to everything else out there sans replaceable high mAh battery.
Possible equal features that are better on other non iOS devices: iTunes Match, restrictions, camera app, maps, multitasking.
So you see it's hard to leave this ecosystem. Especially when the device performs so smoothly at everything. And is damn stable without much issues.
Can't believe I'm going to do this but I'm going to play devil's advocate for just a moment, from an Android user's point of view:
1. No benefit if you don't have other friends/family living in the Apple ecosystem.
2. Can do nearly everything here (photo's excluded, would need third party app) via Google account.
3. Again, outside Apple ecosystem, not a benefit and can be replicated with third party apps.
4. Google Play syncs wireless to all computers, Android devices.
5. No argument from me--nothing in Android world compares (though Microsoft might be onto something with 'SmartGlass.')
6. And limited to Apple only devices, where as a bunch of third party apps (Skype, Qik) can work across multiple platforms.
7. Couldn't say myself so I'll take your word for it.
8. I think this really is device dependent. I've only used a couple of devices besides iPhones (currently using a GNex while I wait for the next iPhone) and the battery life of my Nexus is comparable to my 4s.
Let me qualify this by saying I'm fully immersed in the Apple Ecosystem (iPhones, iPads, iPods, Macs,

TVs) and love exactly what you're describing because it all applies to me as well. However, I also think these points are
more relevant to CURRENT Apple users, thus my counterpoints. If you don't already live in an Apple world, most of these are lost on you. And this is a perfect example of the genius of Apple. Once they suck you in, it becomes that much more difficult to leave. I really truly understood this when I start using the Galaxy Nexus. It's a very good device and Jelly Bean really is
pretty good but it's just that it's a PITA to try to set everything up to replicate the functionality in an Apple ecosystem.
IMO, it's not that most of those features aren't available on Android devices, it's that they demand considerably more time & effort to utilyze, which is great for many Android users b/c they love tinkering, customizing, etc. Me? I just want my crap to work when and how I need it to, and I don't need live wallpapers, 1 less click to turn on blue tooth, root access, tons of folders, etc., so Apple works for me. NOT b/c I'm blindly following a cult and drinking the Koolaide, but b/c it's best for my needs.
Couldn't have said it better myself. I've noticed a few features that I'd love to see integrated into iOS but on the whole, it's just more work to get everything functioning nearly as well and IMO, just not as polished as iOS.