We have a HomePod in the kitchen and its (in my experience) pretty flawless. I empty the milk and I just say 'Hey Siri add milk to the groceries list' and she says 'Ok, added to your groceries list'. If I mumble or stutter things can go off the rails. Also inline editing of my statements causes problems (like where you start saying one word and realizing its the wrong word and swapping it mid-sentence)