Cortana was a squandered opportunity for sure.

Didn’t use cortana directly, but the “auto block out focus time” in my work diary was a freaking game changer and I am pissed they took it away.

I disabled it.

While I didn't use it regularly, I did use it here and there in both W10 and W10M. The jokes were pretty good too. But I'm an old-time halo player that is geeky as fuck so I'm laser-aligned with that demographic.