Okay maybe I am an outlier, but when I vacuum my place (1400 sqft), it takes about 1hr. I fill half of the container with dust. I am kinda thorough, maybe borderline OCD :)

And so I need a vacuum that is not going to lose power, so I am happy to stay corded, with full sucking power all the way.

I can see the Pencil useful for a quick limited vacuuming.