I don't have one, for a couple of reasons:
1) They're not available. As they haven't been much of a success, Apple hasn't even started selling them here in Norway.
2) Lack of eco system. It only supports single account Apple Music, plus Airplay. Airplay is nice, but it's not a substitute for
local apps for other sound services (audiobook services, other mainstream music services, music services for things Apple Music does poorly (e.g. Idagio for classical music), etc)
3) Lack of options. I have a Sonos soundbar in one room, and some Play One/Play 5s in other rooms - even a Sonos Connect connect to my "real" sound system.
If they add an App Store for it and improve Siri, they'll be a much more attractive option.