I just bought a home, and just started a considerable renovation. I'm putting in new water pipes, new electrical wiring, etc. I thought of putting "smart" devices (i.e. switches, alarms, thermostats, etc.) given the "advantages" these promise. After considerable research, it's not worth the hussle or money. Let's put aside the fact that these are considerable more expensive, and won't breakeven in years (some devices…
However, I did go for an electronic doorlock (with finger print reader) and after just a few months I can not imagine ever going back to having regular keys again. If you have a family with small kids and cleaning ladies that need to come and go this saves so much logistic hassle. No need to wait for a delivery man, just give him a temp code to put it in the hall, etc.
There are definitely a few great IoT things, but just like we once imagined a PC would be used to store recipes, we just have to find out what the truly useful IoT things are.