Got a dot a couple of months ago and G home for Christmas.
The Mrs has prime but prime music on the dot is hit n miss, the play lists are very good, but name an artist and it often starts asking for you to upgrade. And you need the expensive family pack to play elsewhere on other dots etc.
Google home is exactly the same from what I can tell when it comes to voice recognition, tricks etc (maybe better for travel info), only I can say play on this or that amp because I already have Chromecasts plugged into stuff. Also Chromecast has digital audio out, echo only Jack and Bluetooth?
Only other advantage of echo is you can change the name to ‘Computer’, could be a deal breaker for some.