I've owned a Windows Phone for a year, only got around to trying Cortana on Sunday evening entirely by accident. It worked flawlessly for adding 2 calendar entries, at which point I was impressed enough to try and engage it in conversation, which (thankfully) failed. All the more impressive as I was a case of beer in, slurring my words, and speaking in a thick local accent that would confuse any Englishman.
Definitely a convenient feature, though I don't know if it has all the knowledge search stuff Siri has, or any of the random pointless gimmicks that iPhone users seem to mainly coo over.
It does have a huge collection of bad jokes, which is a draw to silly people like me! You can even ask it for categories like "tell me a science joke".
Definitely a convenient feature, though I don't know if it has all the knowledge search stuff Siri has, or any of the random pointless gimmicks that iPhone users seem to mainly coo over.