Do they work?
Yes. You would be amazed at what my roomba (I've named it Saul) picks up. I test it every now and then by running a regular vacuum and then Saul. Saul always comes away with quite a bit of dirt remaining. Yay!
Do they have adequate capacity/ battery power?
Meh. I don't have the base where Saul can go charge himself. I wish I did. The new models have it. I usually do the living room and kitchen at one time (plenty of battery power) and then the girls' bedrooms another time. So it could probably do your entire apt. in one or two sweeps.
Would they annoy our downstairs neighbor?
Nope...probably not. Saul isn't very noisy. I don't even take notice when I am downstairs and it is running upstairs. My daughter and dog hate regular vacuums. They don't mind the roomba.
If we have hardwood/ tile floor can we use the Scooba exclusively?
I don't have a scooba but my mother-in-law does. It does suck up dirt before scrubbing with a cleaning solution but I don't know how well it does with the sucking. She hasn't complained about it or raved about it.
Will it clean the bit under the cupboards near the toe boards?
If it can fit under there, yes, it will. I think Saul is about 3 inches tall. Roomba has little brushes to sweep dirt away from walls/corners.
Are they kid proof?
Sort of. If your kid throws it around a lot it might break. Saul has been used as a seat many times and still works. My big fat cat sometimes plops himself on it.
Do you know anyone who raves about theirs?
Nope. But I know people like them. If nothing else it is fun to own a robot. But, everyone I know who has one humanizes it and then feels silly.
Anyone who has had a nightmare of a time with them?
Nope.
how is the upkeep/ maintenance?
You have to clean the brushes and the underside of a roomba. I don't know about a scooba. Not a big deal.
how is the warranty?
No clue. Never had to replace anything. It is probably a limited one year warranty (isn't that what most things have)?