It's fun, like most other people said. And for some things, it's nice.
I have two of my doors with network compatible smart locks with fingerprint readers so I don't need a key to get into my own house, and I have a remote garage door opener that I can fire off with my phone to let somebody in if need be.
All of the entrances to my house have video cameras over them that alert my phone if they detect any movement, and some of my lights are on schedules to let me know when to go to bed because I have problems with that anyway.
Other than that it's kind of nice to be able to turn on all of the lights in my house with a few clicks, although many of my lights are on motion detectors so I don't have to try to find the light switches, mostly in hallways and closets.
The one thing I have left to set up of the stuff that I have bought is a sensor for my front door.
Once it is set up, I will set it so that when I open my front door it will turn on the main light in the living room so I don't have to try to reach around and find a switch.
Finally, it's nice having the peace of mind to know that if I'm away from my house I can double check and make sure all of the lights are out, adjust my air conditioning so that I'm not heating an empty building, and once I'm done with that I intend on setting up a smart watering system so if I'm away from the house during the summer I can make sure that my plants receive enough water.
It's just handy stuff. Makes my life easier, gives me something fun to do, and it can be really cool to watch my house take care of itself without me having to lift a finger.