Roborock E4 was able to dispel my skepticism about such devices. The classic, cyclonic vacuum cleaner was 70% filled with women's hair (at home, in addition to the dog, there are two women). And I rightly feared that the turbo brush would be entangled with them. In fact, this is what happens, but for three or four (I am regularly on the road) cleaning is enough, without visible damage to the quality of cleaning and the robot itself. Of the total 90m2, the robot is available, according to its measurements, from 52 to 60m2, on which it spends from 68 to 78 minutes and about 32% of the charge. There is no direct dependence of time on area.