The Roomba Discovery is the way to go, even if it is a little more
expensive. It has a larger dust bin, its battery recharges faster,
and
it returns on it's own to is docking bay when the battery gets low.
I'm
sorry, but what more do you want from a vacuum?

I'll have a go at this one. I'd like a Roomba that integrates with a
whole-house vac system so that when it docks, it also empties its bin
in addition to recharging. Add to that a timer option where I could
have it make its rounds at a certain time daily.

- Mark.