They both have their uses. I have both, I use both. You can use Alexa to get to Cortana, and use Cortana to get to Alexa. You can use Alexa and Fire TV to quickly view Arlo Cameras. Both integrate well with Wink Hub 2 based smart home devices, and can do so at the same time. It would be nice to get all the smart speakers and displays to play the same music together synched regardless of if they are Google or Amazon based, but that's probably never going to happen. If I had to pick one, I'd pick Alexa because of how many skills they have for it. But I don't have to, because they coexist quite well.