Not sure if this was discussed but I really feel the Google AI (if you can call it AI) is much better than Alexa AI.
For example, Google seems to always understand what I asking, even if I didn't call the device by its exact name. I also feels much more conversational than Alexa. I can also ask Google status of my devices like which lights are on or is the front door locked, something that doesn't seem to work with Alexa without adding some special skill.
Adding Google devices as speakers seems to be much easier as well.
Having said that, the Google interface for adding and changing your connected devices is down right messed up where as Alexa is quite simple.