To see which worked best, testers used the cleaners on some tough messes, including grape jelly, gravy, ketchup, and mud, both wet and dry.
The Swiffer's wet pads, which you buy separately, were better at picking up sticky kitchen spills than the Dyson's, which left some residue behind. But the Dyson was better at vacuuming up heavy dust. The Dyson also comes with a detachable hand vac, which proved great at cleaning up Cheerios. But the Swiffer didn't have any problems with Cheerios either. In the end, Consumer Reports says the $40 Swiffer is a better deal.
If what you really want is a small lightweight vacuum, Consumer Reports found one that's better at vacuuming than either the Swiffer Sweeper or the Dyson Hard. It's the Hoover Platinum LiNX BH50010 for $150. It can't help you with wet spills, but it works well on carpets and did an excellent job cleaning up pet hair.