I have one Echo (the original model) since January 2015 and love it. It is an awesome value if you have an Amazon Prime account, as you can stream from their catalog.
It also doubles-down as a bluetooth speaker, can stream from both web radios as also local radios (if they have an internet version).
Provides news as also weather forecast, you can set alarms and timers.
I haven't used it yet for home automation, but there are quite a few products (e.g. smart bulbs) that are compatible.
I imagine that the Dot should do it all as its bigger brother, but maybe the sound quality won't be as good given its small size. But IIRC, it has an stereo output, so you could pair it with a bigger speaker.
DOT has Blue Tooth capabilities to go to a remote speaker...