Re: I've said it before...
You have also summed up the big problem with things like Cortana; you are impressed by it doing things that Apple and Android have had for years.
I have a Nokia 520, and it does what I want for the right price, but don't have Cortana yet. Even when it comes, still going to just another catch up feature, but probably not quite as slick as the integration with Google on my Nexus 7 tablet. I don't use Siri, but it is a couple of years ahead of Cortana in development.
Thing is that the 520 is nice little low end phone; if they kept building up that modest success with small regular improvements, then maybe my next phone would be the next model up. Instead the newer devices in the range (like the 530), seem worse if anything, and the app situation is not improving; one app I used on WP8, is now defunct and no alternative is available.
I think phones like the HTC one, seem like afterthoughts - stick a model out there, same hardware but with WP and few Microsoft people might buy one, but given the same hardware for the same price could be running Android with more developed features and far more apps, I can't see any appeal (and that is from somebody with a WP8 phone)