Owned every single iPhone until the iPhone 4, switched to the Galaxy S4 after that and never looked back. The S4 is better than any iPhone in my opinion. It's got a bigger and higher resolution screen, it's more customisable, it has very cheap expandable memory (£20 for a 64GB micro SD vs £200 extra for a 64GB iPhone), it has apps iOS just will never have without jailbreaking, a process that's becoming harder and harder with each new iOS update (I got torrent clients, "adult" apps, system utilities, etc), and to top it off even the latest S5 is cheaper than the iPhone on most contracts (in the UK at least), and the Note 3, as it's about to be replaced, is a lot cheaper, despite still being a complete beast. It's even cheaper than the 5S. And the Nexus 5 will give you a device comparable to the S4 for just £300 new with stock Android.
And if you don't like any of those phones? Cool, there's like 10 more flagships to choose from. Maybe you dislike the plastic on Samsungs? Buy the One M8 instead. Maybe you want a smaller screen? Samsung, HTC, Sony, Motorola, and more all do smaller Android phones. You have a plethora of choice. Apple gives you three choices: the iPhone, the cheaper iPhone with the specs of last year's one, or the one that's two years old.
Quite frankly after owning my S4 for a year I can't help but feeling I've just let Apple con me all these years I got iPhones. I could easily keep the S4 for another two years and still have a perfectly good phone in my hands. I have it underclocked to half the stock speed to boost battery life (because Android lets you do that) and it's still blazing fast. In fact I'm only looking to upgrade not out of necessity but because I feel like copping a phablet. And it will likely come from Sammy because overall the S4 has treated me very well (only one serious problem but that was a CynogenMod bug, not Sammy's fault). There is just absolutely no way I could ever justify another iPhone after enjoying what Android has to offer.
And with Android L dropping in a few months there's never been a better time to jump into Android. L is as refined as iOS but with none of the downsides.