Roombas are a great idea in theory, but having a vacuum that doesn't work all that well bump around the walls isn't as great as the idea of a robotic vacuum. That's why Dyson has been working on their own robotic vacuum for over 16 years. The Dyson 360 Eye uses the pattented Dyson cyclone technology to really step up the cleaning power of the device. It also has a 360 degree camera that records where the device has already cleaned and where there are obstacles to block its path. The result is a better, more efficient robotic vacuum -exactly what you'd expect from the Dyson company.
Read more about the new invention over at Homes and Hues: The New Dyson 360 Robot Vacuum
The issues I had with my Roombas (since 2005) have been that hair has gotten into the mechanism and slowly destroyed gearboxes, that the same hair have been an awful lot of work to clean the brushes and that the batteries dies after a few years. I've never had a problem with it not cleaning properly.
I haven't seen anything about addressing those problems. The Roomba 880 addressed the hair problem - or so they say.
I also have a Neato for comparison, another actually mapping/navigating bot. It also doesn't have the corner/side brush, so it never cleans properly next to the walls. I assume the Dyson will have the same issue there - in their video they show that the side brushes don't always work (always worked fine on my Roomba) but doesn't offer a better solution.
But what in the end will keep me off the Dyson is that it wont clean under my furniture. It's too high.