I have definitely known too many people to experience issues with missed calls on iPhones to ever consider buying one. I have had android phones since the HTC Dream and I have never had something as simple as that go wrong - although the 911 bug seems far worse; I've just never met anyone with that problem.
My Nexus 4 developed an interesting one after the update to 5 and 5.0.1. Incoming calls would crash it half the time, or 5 seconds of silence on calls that didn't crash. The dialler was almost unusable.
Was widely reported but never properly resolved, so that was the cue for replacement.
My Samsung Note 3 got so laggy that I couldn't get the unresponsive phone app to actually pick up the call before it flipped to voice mail. Reboots would fix it temporarily, but it would come back. You have failed at your primary purpose, phone. Android experiment over, back to iOS.
I know plenty of people including myself that experienced it with Android phones. Weirdly, one of the most stable Androids I owned in terms of phone use was my Xperia X10 — one of the first android phones out! I miss that phone. And my Nokia N9.
