I have been using the Amazon Echo for a few months now and have grown to be quite fond of it. I mostly use the alarm and steam from Amazon Music or Pandora. One nice feature is the ability to ask for the song which is being played. That way, I won't have to rely on Shazam whenever I discover a new song which I enjoy.
The one major downside so far has been that I can not connect it to my Logitech 5.1 sound system, as it has no external audio connections. I suppose I could get the Amazon Dot and hook it up to my speakers, while I relocate the Echo to the living room or kitchen.
Alexa has been very responsive to my voice commands, even when playing ambient music in the background. There were a few occasion where it did not execute the correct command but 99% of the time, she is spot on.