Amazon Exho/Alexa is doing overall a good job in my house. Yes technicality it can listen to every words we say at home, but until now it didn't bother me much.
I found out recently one guy that had the time to get Amazon Alexa SDK / voices to work in conjunction with my Nest thermostat and recently SmartThings did integrate with the Echo too.
So it is now extremely convenient for asking Alexa to set the temperature by voice without the need to lookup for my phone or tablet, same in the evening to simply turn on the lights in a few places.
I do think that Voice Control in home automation is going to be a big plus.
How sensitive is an Echo wrt positioning? What I mean is, do you have to put it in a location where you can talk in its direction or do you just put it down and even when you face away from it (let's say, from the couch), it still picks up what you say?
And does it do the voice recognition on Amazon servers or does it do that locally? Well my underlying question (since I can google technicalities like that...) is, how is the latency?
My only gripe about the Echo is how 3rd party apps are integrated. I'd prefer it to be seamless. "Alexa, good night." should result in my HA system running a night-time scene. The current “Alexa, ask {Greeter} to {say hello world}.” is cumbersome and breaks the natural language flow. We should be able to have a conversion with the computer, not give it properly structured commands.