The killer feature on android for me has always been widgets. I get a bunch of information immediately available without having to open an app. The second killer feature on android is definitely Google Now. I rely on it everyday.
But coming fresh off the hoopla that is WWDC, and being a lifelong macintosh user, I feel myself more and more swayed to jump both feet into the Apple ecosystem and get an iPhone. I've never been an iPhone user, so I can't speak to its real-life use, but I did have an iPod Touch once upon a time, and as soon as I was able to, I jailbroke it so I could tailor it to my liking.
This is probably the biggest change in Apple I've noticed. The slight cracks they've created in the iron fist of control. Third party widgets and keyboards, opening up Touch ID, Health Kit, and home automation - it's things like this that tell me, maybe now's the time to make the switch. I don't have any issue with Android, per se, I just see the ease with which things could happen when I see all the cool stuff with the "continuity" implementation.
But then again, after I watch the keynote at Google I/O in a few weeks, I'll probably feel better about sticking with Android.