It depends on what they mean by "little things". Basically, the sensor detects something in front of it -> robot slows down until the front of the robot touches the obstacle. If the resistance of the obstacle is high enough to trigger the touch sensor, the robot stops and turns until it passes the obstacle. If the resistance is not high enough, it pushes the obstacle in front of it (rather rarely - it must be quite light at the next wall to trigger the sensor anyway).

Small parts are sucked in, you have to take them out of the collection container before you empty it into the waste. However, this is much less tedious than with the hoovers with a bag.

The robot has trouble with carpets that are very light (floor runners made of fabric), which it then always pushes around the flat or until they throw "waves" and the resistance becomes too high and the robot thinks it is an obstacle. This does not happen with real carpets that are not too thick, the robot drives on them and the increase in suction power is clearly noticeable.

Another important point (I have had an IRobot for several years and just bought the 980 because my old 580 had to retire) is that the robot does not replace hand vacuuming, but if it runs 2-3 times a week, it picks up most of the loose dust in the places where you spend most of your time. In the kitchen, it can also pick up all the crumbs that fall on the floor every day and spread around. And that is also the huge advantage that such a device offers. It's also good for regularly vacuuming the dust under the sofa and beds. The hand hoover is used once a Monday to vacuum the places where the robot can't get to.