We have no carpeting, and bought a roomba. It worked wonderfully, never got stuck, and had this genius side sweep spin brush that got things out of crevices you wouldn't imagine, i.e. it picked the dust bunnies that were stuck to the felt pads of our table and chairs). We swapped it out though for a mint and a neato. We live in an apartment building, and the roomba does random patterns on the floor until it has covered a room three times. We thought that was too long for our downstairs neighbors to have to endure.
Pros- Roomba does the job for you. It can be set to operate while you are out, it gets under furniture, and is really good with dust bunnies.
Cons- It takes a while to vaccum. It requires you to pick up (I don't regard this as a con as we pick up anyway). You will need to vaccum every so often anyway, to get the baseboards, etc.
I say go for it, buy one from a place with a solid return policy. You've got little to loose in giving it a try.
Good luck to you and yours,
F. B.