I use Cortana all the time now. I've posted here before how it feels like Star Trek, and it impresses me more and more as time goes on.
Example: The other day I said to my phone "Hey Cortana, where are some coffee shops with wifi around here?" And, you know, it worked. It even used the speech synthesis to talk to me. It's eerie having a conversation with the phone like that, using natural language, not even trying anymore to treat it like a computer (e.g. careful phrasing or enunciation).
I seldom open maps by hand anymore, but I ask the phone for driving directions all the time. I never set my own alarms, and for a long time, didn't know how to on this phone.
I don't use all the features Cortana has, like the flight tracking stuff, but I can see getting into the habit with that, too.
It just blows my mind how useful it is, and how little thinking I put into engaging with it as a computer-driven system anymore. Cortana's my first "it just works" experience with a computer, like, ever.