Damn, that little thing picks up a lot of cat hair! I don't have a big space, and I use the virtual wall to keep it out of the bathroom (just easier to do that room myself than to keep getting the Roomba unstuck), so it covered basically the entire space in 35 minutes before the bin filled up. I imagine if I run it every day, not as much cat hair will build up and it will run a bit longer before it fills up.
I am going to run it again today to get more hair out of the carpet, but I will give the girls a break and do it a little later. They're all settled in for naps at the moment, so I don't want to disturb them again so soon. Although the Roomba doesn't freak them out nearly as much as the regular vacuum cleaner does (regular machine is much louder and scarier!), neither have tried to ride it yet, which is very disappointing.