Most uprights hold one gallon, enough to clean one room, and shut off automatically when the dirty-water tank is full. With filled tanks, most of these models weigh between 25 and 30 pounds, something to keep in mind if you have a small build. With their lightweight wands, canisters tend to be easier to clean with, since you don't have to push around a 25-pound machine . But you will have to lug the 30-pound canister, and if you have stairs, this can be even more of an issue. Also, changing tools isn't as easy as with uprights.
Canisters usually hold two gallons, which means less time spent filling tanks.
The downside, though, is that the water may cool off before you use it all. Keep in mind that deep cleaners won't make your carpet look brand new, especially in heavily trafficked areas. Frequent vacuuming and spot pre-treating will increase an extractor's effectiveness, but none of these machines will completely remove any tough stains that have been in your carpet awhile. Not only does this unit deep-clean carpets, but it can be used to wash, scrub, dry, wax, polish and buff bare floors. It comes with 12 different brushes and pads, but keep in mind that you have to manually change them for each function.