It's hard to say if a wet-dry vacuum is better than a mop — it's just different. With a mop, you have to expend a lot more energy and strength to remove stains on the floor. With a wet-dry vacuum, it does the work for you. Some, in fact, have ultra or max modes that expel more water and solution to help break down a tough stain. As Mock suggests, look for wet-dry vacuums with "higher wattage or horsepower, [as it] generally indicates better performances when dealing with wet messes."

That said, she advises folks not to get rid of their mop, as she believes it can provide a deeper clean than a wet-dry vacuum. "For a more thorough cleaning, vacuuming first and then using a mop can be more effective since vacuuming removes debris and dirt, and a mop can focus on removing stains and grime," she explains. 

Now to be clear, wet-dry robot vacuums aren't going to give you as deep of a mopping experience as a regular wet-dry vacuum, but they'll keep your house fairly clean between deep cleaning sessions.

Yes, you can use wet-dry vacuums on hardwood floors as long as they're sealed. Some wet-dry vacuums have more water output than others, but among the ones we tested, the water output is not too significant to cause concern. That said, you don't need to mop your hardwood floors more than once a week. Always check to see that the wheels don't cause any scratches on your hardwood floors. That did not occur with any of the wet-dry vacuums we tested. However, we did find some wheels glided more smoothly on our hardwood floors than others, like the rubber wheels on the Tineco S7 Pro. Lastly, some cleaning solutions could damage your hardwood floors over time, so it's probably best to use the cleaning solution provided by the wet-dry vacuum only once a month. 

According to Marla Mock, president of Molly Maid, a Neighborly company, "Wet/dry vacs and mops are all better suited to clean hard floors, while vacuuming is better suited for rugs or carpets. If it's just a quick clean-up, then wet/dry vacs are better since they combine the functionality of both vacuuming and mopping."

Some wet-dry vacuums can be used on low-pile rugs, but most of them can't be used on carpets. So, if you have carpet, you'll absolutely need to keep a vacuum on hand. Vacuums are also multi-functional and can be used to clean cobwebs from the ceiling or used as a hand vacuum to clean messes on your couch. They're also perfect for cleaning up debris quickly, compared to a wet-dry vacuum that takes time to set up and use.