I've had an iPhone since the original came out. It wasn't until earlier this year I tried something else. I tried the Lumia 900 for awhile and now have been using the Galaxy Nexus for a good while now. I don't know why we get locked into these debates over which is best. For intents and purposes I will just compare Android and iOS; to me all Android phones are the same but either with a skin or no skin. Better is subjective and no one will ever agree. They are just different, but not really.
Honestly, after using Android IMHO it's literally the exact same thing as an iPhone. The only difference is that you can customize it and swap out stuff like keyboards, spring boards, and really what ever else you want to do. But at the most basic level with stock Jelly Bean, it's the freaking exact same thing. Rows of app icons on the screen. There isn't a single thing Android does that I couldn't do on my iPhone usability wise. In fact there are several things I miss from iOS such as the universal inbox; I hate email on Android. The only thing the iPhone can't do is customize the OS and phone to your liking. That's really it IMO. The apps even all have the exact same UI, function the same, and display the same content.
When I got into customizing and messing with Android though is when I actually started to like it the least. After loading up a new spring board and trying to make it look really cool I found that in every day use I was forgetting how to do something. Many times I was like, wait what happened; oh yea I changed that two days ago. So now I'm on stock Jelly Bean. I find I use it just like my iPhone. Widgets were neat for about a day. Then I found they were just in the way and didn't really give me any useful information. Some apps are lacking. I haven't yet found a good basic list app. I also haven't found a comparable bill reminder app either that I like. Many apps also ask for ridiculous permissions such as a list app I tried wanted permission to see my phone calls. Then every time I got a call this little pop up that was completely useless would come up. Lots of apps are like that.
I am in love with swiftkey 3 I will admit. Apple should buy them because this keyboard rocks hard and blows away anything else on any platform. While I do find the big screens nice when reading stuff I do get annoyed when UI elements are poorly laid out and I have to stretch my thumb across the screen. But bigger doesn't mean better to me. It's just different.
I'll sum it up. The S3 just doesn't bring anything to the table that wows me and is like I must have that. Big screen; that's cool. More RAM; neat. SD card slot; OK. NFC; maybe some day it will be useful. Wireless charging; now that's interesting. Touch screen that works with gloves, say what? A hardware stabilized camera; haven't seen that before in a phone. Un-scratchable polycarbonate body! Where can I get one of those? Oh yea; it's called the Lumia 920. Give me something something I haven't seen before and I'm interested. But the S3; been there done that.
In the end though I've found I want to spend time actually using my phone and just pick it up and go. I don't want to spend weeks getting everything little thing tweaked. I'd rather spend all that time living instead of setting up my phone in an endless loop of customization.
But this debate will never end and is useless really. It's no different than debating if green peppers are a better pizza topping than onions. Or that the Xbox 360 is better than the PS3. Everyone likes what they like and buys what they want to buy. Why does that seem to get people so bent out of shape?