All the way cool. Strong but unobtrusive! It sucked up the soil from my flowers, the flakes from my dry skin, and the heavy, coarse hair from my dog. By the way, since these aren't regular brushes but rubber, they clean up well. So that you don't forget to clean the canister more often than once a month (or whenever the dog destroys something again), we considered purchasing a self-cleaning station for our vacuum cleaner.