Officially made the jump from android to iOS 2 days ago after 2 years with Android. In the last few months I was ready to throw my Galaxy Nexus out the fucking window. I get that there are some things to consider, such as, well... the phone was two years old. But still, over time, this phone got slower, and slower, and slower. It got to a point where if I used anything but stock keyboard, the keyboard would take at least 10-15 seconds to load. Any time I needed to look something up in the last year, I wouldn't even bother pulling out the phone if I had my ipad nearby instead. Even after a wipe of the phone, it still behaved very slow.
Battery life was another issue, which is a common complaint I see a lot with most Android phones. I've had issues in the past year where if I've gone to a city, I would have to turn the phone OFF completely out of fear of the battery draining for no reason. I realize this is probably better with the newer phones, but battery life was by far my top concern with picking a new phone, by far. If the phone is dead, it doesn't matter what other features it has, because the phone is fucking dead.
How smooth the software behaves is another top concern for me. Like I mentioned before, the galaxy nexus inexplicably became slower and slower over time, whereas my ipad has always been a joy to use for almost two years now. No crashes, other than occasional pages closing on the ipad, and I can simply bring them back up again. The Galaxy Nexus over time became slow, would crash sometimes completely when I needed to make calls, etc. I've toyed around with the better android phones available, and there's STILL some lag when scrolling and opening pages.
I realize I'm comparing apples to oranges here with a tablet vs a phone, but it made me realize how important the phone is to me and how smooth I need it to behave. I do like android a lot, but iOS has never let me down for what I need to do. And no, I don't want to root a phone and load a rom to get my phone working at its peak. Why should I have to? I bought the phone, shouldn't it already be working at its peak? It's like buying a console and being told "Yea, it works pretty well, but you really have to fiddle with it and constantly toggle settings to get the games working the best." I really don't feel like going through that, not after my experience with my phone for the past two years.
A last reason I switched was because of how fucking long it took to get updates for my phone, if ever. And that's more the fault of my carrier, fucking verizon. Still, it's irritating to have to deal with those waits when you know there's a better update available for your phone but it's being held back.
So yea, experimenting with iOS for the next two years. There's stuff about android I loved and I know I will miss, mainly google All Access. The integration of your own music and music you add from their catalogue is amazing, and they seem in no rush to make an app for ios. If I feel like I've made a terrible mistake in two years, no biggy, I'm sure android will have some very drool-worthy phones out in 2015.