And more importantly than just features, the high rate of latest-OS-adoption on iOS means security updates get out fast.
This has a side effect of "herd immunity" in that iOS is a less-desireable platform to develop exploits for than Android, since the shelf life is much better for an android exploit.
I'd love to see google innovate here, for now it seems like they're not even trying to match Apple when it comes to this metric.