At this point since I have more experience with the Echo’s I will say they integrate really well with lots of stuff. The one and only reason I’m interested in the google mini’s is the broadcast feature. I want to play with that and see how well it works. It’s a cheaper system than buying several raspberry pi’s and speakers to have whole home TTS and media capabilities. I don’t need whole home audio I have that through the Echo’s.
I do have a few TTS things setup that I like and would like to have a “cleaner” solution than rpi’s everywhere with speakers attached and I have some media clips I like to play when certain events occur. If the google mini can fill those gabs that I can’t currently do with Alexa that will be great.
The next best is the expensive route and either buying Sonos or Samsung or Bose speakers around the house and that, to me is way too much for just TTS and playing mp3 clips on events.