Personally I'm not into replacing working devices. If they're problematic, then I would upgrade too.
The Inovelli Blue seriees would be my personal preference for Zigbee switches. The Inovelli White series is Thread only, so you would need a device that can act as a Thread Border
Router. Depending on which Google Nest device you're talking about. The first generation Google Nest hubs cannot function as a Thread Boarder Router. Hubitat Elevation hubs don't have the ability to act as Thread Border Routers. The C7 (still in Beta for Matter), C8 and C8 Pro can connect to other Matter devices via IP, so if you have a device that funcitons as a Thread Border Router, that is how you could connect Thread devices to Hubitat.
I still use mine. My preference is to keep those Zigbee bulbs on their own network. Some say they don't have a problem. History tells me different in my home. Besides, I like the apps available for the Hue Bridge. It's not broken, functions great, so I'm keeping it just as it is.
I use Echo Speaks, or I use Alexa routines. If you're not an Echo owner then I don't have a good answer for you on that one.
I have three of the v1 Aeotec HEMs. Chatty, but I don't find them finicky. Two live on my secondary C7 hub and the third is joined to Home Assistant. They're good devices. In fact I have no issues with these and others with later generations seem to have lots of problems.
I have two. They're fine. There's an issue with disabling Description Text Logging, but I wouldn't be concerned with that. Mike Maxwell will have that fixed in the next release.
I have one, but never installed it. Good device though. I instead use Moen Flo. There's a community driver for it, but communication is cloud-based. Very relieable cloud service though, as one would expect from such a product.
@kkossev Has done some work with drivers. Some say they don't have any issues with them on C7 or C8 hubs. Personally, I decided long ago I wasn't going to fiddle with them on HE anymore. They're great devices, with excellent battery life and their very small. Didn't want to give up on them and I had heard they were very stable on HA. They are in fact 100% rock solid on HA. So all of my Aqara/Mijia Xiaomi devices, in addition to some IKEA devices, are joined to Home Assistant and I use Home Assistant Device Bridge to bring their states back into HE for automation. I've been using this setup for over two years and it's solid. No drops EVER.
