I use both Zigbee and Z-wave. I am more partial to Z-wave, have used it longer and have a back collection of Z-wave devices. The Z-wave mesh is very strong and reliable in my home.
The zigbee mesh is non-existent but does work. I have the hub, which is compatible, and then about 20 sensors. I have issues with sensors dropping in and out. This is because I do not have any zigbee repeaters and all the work is carried by the hub. I am ordersong some zigbee repeaters to replace some of my z-wave wall modules to help with this. I think we determined in another post one for every 5 sensors.
I will have a minimum of 1 z-wave and 1 zigbee repeating device in every room starting at the hub. I believe this plug here will actually repeat both protocols (Iris Model 3210-L):
Purcahse: https://www.lowes.com/pd/Iris-120-Volt-White-Smart-Plug/999925330
Discussion: [OBSOLETE] Iris Smart Plug (3210-L) Zigbee Plug with Z-wave Repeater
You cannot go wrong with either and I see great benefit in going with both. Just make sure you plan out your “mesh” in advance so you don’t leave any devices out.