While the Roomba is practical in sucking up dust, I'd like to share info from personal experience.

There are four people living in my home and we have an American Eskimo dog. He's got medium length fur that sheds quite a lot and the three ladies of the household have long hair. This is a nightmare for maintenance of the Roomba. It gets clogged every few days and I can't find the energy or the time to de-clog it and when I do, I find myself wishing my dad didn't spend any money on it. You also need special equipment to clean it. And by special equipment I mean a face mask for when you empty the dust pan and a screw driver for unscrewing the rotating brush in case there's hair tangled there, and an accessory provided by Roomba to untangle hair from the brushes.

So if you have a pet or live with people that drop a lot of hair (or don't quite have the patience for the maintenance), the Roomba isn't for you.