Then I tested a few more devices.
Belkin WEMO LED Lighting Starter Set (two smart bulbs and a control device) -- After 20 minutes, I wasn't able to get it going and I ran out of time.
D-Link Smart Plug DSP-W215 -- I didn't have too much trouble getting it to switch a lamp off and on. Maybe 20 minutes. Account signup was required.
Insteon Starter Kit (Insteon Hub and two Dimmer Modules) -- Good setup, no special trouble.
Now here are the problems.
Nobody in their right mind except a nerd like me is going to have the patience to put every new bulb on their system, complete with IP address. To be fair, some don't require an IP address, but it still isn't easy.
Every package requires an app. I downloaded the wrong WEMO app the first time because there are several.
Every app works differently. You have to study them to turn the switch on or off.
They are expensive. This will improve over time, but how soon?
Tech support on these must be really awful. OK sir, now turn the light switch off and back on five times to put it into the rescue mode.
Firmware updates were required several times.
For security, these must be a Bad Person's dream come true. Each manufacturer usually requires an account signup, and then the devices need to connect to your access point, so passwords are littered about freely.
Insteon and others have a different and, in my opinion, better method. They only require that a single device (a hub) be connected to the LAN, so authentication is only required once. Their devices are discovered by the hub, so they appear in their app without having to manually connect each one. Insteon also uses another nice strategy. The hubs use both the LAN and the power line to communicate.
Mesh networking is important for the devices that use the ZigBee and Z-Wave protocols. Each device relays what it receives, so bulbs at the other end of the house work.