Having been using both for the last month +, I find I will never get rid of my iPhone and will in fact keep preferring it....
I'm getting sick of tweaking my home screen....I can't seem to get it the way I like it and, to be honest, am suffering from having TOO much freedom it would seem....
I guess the things people hate most about iOS (the keyboard, small screen, settings) aren't all that bothersome to me.
I can leave everything on (BT, WiFi etc.) so there's no need to go searching through the settings menu because the battery life is so much better on my iPhone 5 than it is on my Nexus 4.
The keyboard, while pretty slick on the Nexus 4 (I like gesture typing), isn't really a big deal for me as I don't use the predictive text on either hardly at all....I find it more of a pain to stop typing and see which three words Android thinks I'm trying to say and then pick one of those than simply typing it right in the first place (which I generally do).
Using both side by side, its pretty obvious while smooth, Android still doesn't match up to iOS. Project Butter is great, and I wouldn't characterize my Nexus 4 as slow or laggy at all.....simply that my iPhone is just faster. Its like retina vs. non-retina for me....give me both side-by-side and I'd notice. Give me them separately and its not as apparent.
I have other little annoyances on Android - the sharing menus are freakishly long and cumbersome, the default view in email is zoomed in so I can't see the whole thing and navigating the email is a pain, constantly monitoring my battery/apps to make sure nothing is going rogue (although JuiceDefender is great and does a lot of this for me now), and the notification light (LightFlow) is more annoying that helpful.....especially when it blinks for no reason (I get my green light - meaning email - even when I don't have an email sometimes.) Play music is awful (the app itself, not the service which if fantastic), the fact that I have to approve ridiculous permissions for random apps is a pain, and the stock messenger handles picture messages and MMS very poorly...
Of course, there are things that are great about Android.....I like the Direct Dial widgets - probably my favorite widgets and I realize that many of my issues could be changed if I found the right apps to do what I wanted to do....
But that's where I go back to iOS....
I have a wallpaper of my wife and I on my lock screen and a nice picture on my home screen. My apps are ordered and arranged how I want them - I don't need any more "customization" than that. iOS works for me out of the box - the stock email app, while somewhat limited, is much more intuitive IMO. iMessage is awesome and iCloud services (especially cloud backups) are second to none. Not to mention, the display quality on the iPhone 5 is superb (not a fan of AMOLED, and no other LCD that I've seen, save maybe HTC's One series matches the iPhone 5).
There are other things I could say, but this is already too long.....point being:
I'll continue to use both side by side - my work and personal phones are separate (as I like them to be, despite Samsung's commercials) so I'll continue to use both platforms. But unless Apple does something really stupid, I can't see preferring Android - iOS (and the iPhone) are too well built....fluid, efficient and care-free. Onthecouchagain is going to cringe when I say this, but the iPhone, for me, "just works".