The bulbs are very bright, even when just using colors instead of white light, with a high range of brightness available. I can't speak for their Thread functionality because I don't have any other thread devices, but the Bluetooth can be a little spotty, in general though they seem to connect just fine to my Google Nest Audio. I do wish the app offered some more features, it feels a little lacking as you can currently only set a static color/brightness, but nothing dynamic other than the Circadian Rythm which I don't think has worked for me. I have been able to set automated routines through the Google Home app though. I assume more features will come with future updates.
Overall they are great bulbs, they are very attractive in their design and offer excellent colors/brightness, I just feel the software is a little low on features at this point.