I've had it for over a year now and it still rocks.
My house has seen a lot of people, pets and messes but it keeps up with it all.
As an mechanical design engineer I can think of a few improvements to the clean-up of the unit but other than that it works great!
Not having to sweep but once a month by hand is so worth the $400 but I spent.
The amount of finedust it picks up is amazing too.