With some excellent assistance from @phillip1 I am going to have to echo this post.
The SeeedStudio Human Presence Module tries to be too smart for its own good is not really comparible with the DFRobot.
The DFRobot is adjustable in distance and milliseconds. This means you can be 6" away from it and it won’t trigger if that is what you want. The SeeedStudio on the lowest sensitivity stays “ON” for a three bedroom apartment.
The SeeedStudio stays “ON” for ages when you might think no one is around. The DFRobot can be set to a delay of 25ms increments.
So from a use-case perspective - if you want “movement-based” detection in milliseconds for individual rooms. Get the DFRobot. Combined with a PIR, it makes an excellent motion lighting sensor. Fast and reliable.
If you want to get away with fewer sensors and can live with greater on-to-off latency, get the SeeedStudio.