I fell for Google Now when I booted my old Nexus to test test something, and Google Now had read through my emails and showed me a tracking status for a UPS package I was expecting. I was pretty jealous of that functionality, but never convinced to go back to Android just for one feature. Now, I really have no reason.
It's also pretty telling of something when more iOS devices have Google Now than Android devices do.
It's also pretty telling of something when more iOS devices have Google Now than Android devices do.