Not a big popcorn fan so I haven't used that button on my 2.2 cu ft Sharp 1200 watt microwave. It does have this water vapor sensor though.
Works fairly well with vegetables and things like potatoes. Yet you might have to regular power add a minute to a minute and a half.
Careful if your using the butter softening button. Put it in a bowl because you might totally melt the butter. Had that happen. 😆
These water vapor sensors are not that bad though.