I just ordered an Echo as Christmas gift for my wife. She is excited about using it as voice-responsive Pandora speaker. This works in our house because of a wall-less floorplan on the first floor which will allow it to be used and heard throughout the living space. I'm looking forward to installing smart bulbs in my kids' bedrooms so that I can turn off the light they never seem to remember.
I friend of mine, has bought hard into the smart home concept and uses Alexa to run every light and most small appliances in his house (even a custom design to allow Alexa to flush the toilet). If you are willing/able to commit to the smart home concept completely, the commercials accurately describe the user experience. However, I belief most of will have a slightly less satisfying result.