It doesn't like rugs with fringes, NotSpaghetti - they catch and pull, and make the motor shriek. I solved this by removing the fringe on mine. No-one has ever noticed. If you leave a thin scarf trailing onto the floor where it can get tangled in it, the same happens.
It does like chair and tablelegs. Every time the robot bumps up against one it goes carefully right round it. The carpet is probably twice as clean around chairlegs. If I remember I upend dining chairs onto the table.
If you programme it to clean when you are not around (still in bed?) you need to leave the doors open in the rooms it is to clean. Wide open, not half shut. Mine pushed open a nearly closed door just enough to get in, then when it returned it bumped it closed from the other side. I found it sulking in a corner of the room when I eventually went in there. It had been unable to get out and back to its charging station, and had kept vacuuming until its battery ran down.
A plus - every time she was here, my teenage granddaughter begged to be allowed to get the Roomba to hoover the carpets.