I love our Alexa! We have an Echo Plus in the living room and a Dot in both the kitchen and our bedroom.
I pay £79 per year for Amazon Music Unlimited as although the music service which is free with Amazon Prime is very good, it didn't have the wide range of music I like!
We're gradually replacing all our light bulbs with Philips Hue, so control almost all lighting via Alexa.
We haven't got her controlling the heating as we're perfectly happy with the system as it is.
I do find her useful for randomly turning lights on and off when we're away simply by using my smartphone!
She's a great way to get the news or weather forecast at any given moment.
Also great for confusing DH when I switch all the sitting room lights off from upstairs, leaving him in the dark, both literally and figuratively!
We bought ourselves Alexa mid January, and were quickly so impressed with her that we bought DS & DDiL an Echo Plus and two Dots for their Anniversary last month, they're just as 'hooked' as we are! Our DGS, 18 months, even says Alexa and she switches on, but so far she doesn't understand his version of "Play Grand Old Duke of York"!
I have no intention of ever getting her to lock and unlock doors, I like to do that physically!
Just a bit of advice, if anyone is thinking of getting an Alexa, get the Echo Plus, as it has a built in bridge/hub to operate lights, electric sockets etc and is basically more 'future proof'!
Kitty I also say "please" and "thank you" to her, manners are ingrained 