A few additional notes:
1) The Pi 3B+ has 5Ghz wifi in addition to 2.4 Ghz but to enable it I had to set the WiFi Region code (so it knows what frequencies are valid in your area).
I did this via:
sudo raspi-config
And under the Localization Options, WLAN Country choosing the proper entry for me. Once I did that and rebooted I was getting a 5Ghz connection. Note that the ifconfig and iwconfig commands can be helpful in checking your wifi and ethernet connections.
2) I tested out the available ethernet connection as well, which works but I was getting an internet connection to my router for both the ethernet and the wifi. I messed around with turning off the wifi radio but decided in the end to leave both enabled but disconnect the ethernet cable - so I am using just the 5Ghz wifi connection. Seems like a good backup connection plan to be able to use the ethernet connection should there be a wifi issue. Note that you will get a different IP address for both your wifi and your ethernet connections, so keep that in mind when using Putty (or some other program) to connect to the pi.
3) I updated Raspberry Pi OS on the Pi 3B+ once it was up and running. I thought this was a good step as it would both update things and hopefully also add anything that may have been specific to the 3B+ vs the Zero W:
https://www.raspberrypi.org/documentation/raspbian/updating.mdObservations:
Functionally, I do not see any differences in running HomeGenie on the Pi 3B+ over the Zero W. Everything seems to work the same, which is good. I do not have any devices attached to the Pi with the exception of the CM15A (the x10 controller).
Performance wise, the 3B+ definitely loads HomeGenie much faster and the response time for devices also seems faster. I am hoping once I add in the Smartenit to replace my Smartthings interface (that I use for getting Alexa to talk to HomeGenie for my X10 devices, I have not used HaBridge in over a year) that my upgrades will be complete