Robot vacuums have climbed to a new level. Literally. What happens when a category clears a major hurdle? I wrote a while back that robot vacuums don’t work in my house. They’re just not feasible, with too many stairs. Four different levels. Split landings and thresholds. The robot we tried noisily cleaned one floor and ignored the rest of the architecture by default. That limitation has been structural and fixed since the very first version. But at CES 2026, Roborock showed the Saros Rover,...