I am using Hubitat for all my z-wave and Zigbee devices now (after latest IKEA firmware updates).
And of course, for all my automations!
SmartThings - use the mobile app only, undoubtedly much better than HE. A small number of all my Hubitat paired devices (thermostats, temperature/humidity sensors, water leak sensors) are pushed to ST using Mira local integration)
Aqara E1 hub - for one Aqara Smoke detector (hopefully will manage to handle it locally from HE soon). And for sniffing Zigbee devices protocol when needed.
Apple Home Pod hub - for one single Thread T/H sensor and for testing.
Home assistant w/ Zigbee2MQTT and ZHA - for testing, also for bringing some Xiaomi WiFi devices to Hubitat.
Tuya Zigbee hubs - for sniffing the Tuya-specific Zigbee protocol (needed very rarely now) and making the devices work locally on Hubitat : )
I forgot the Philips Hue hub - a rock solid solution for controlling almost all of my lights, integrated to Hubitat via CoCoHue.
