The Roomba you can confine to a certain area using their "virtual wall" devices. The Neato uses magnetic tape placed on the floor to limit its path. Neither, AFAIK, can be told to clean a specific room without having to physically pick it up and place it in the area to be cleaned. That would be a nice feature, though.
My Neato can do 90% of my first floor, finds its way back to recharge, and complete the rest of the level. I still get a kick out of how well it navigates the house and can find its way back to the docking station.