I have a Roomba. It simply doesn't work well. There are always spots that are missed in a medium sized room even when I leave it running for half an hour. I jus

I have a Roomba. It simply doesn't work well. There are always spots that are missed in a medium sized room even when I leave it running for half an hour. I just end up vacuuming the place myself since it takes about a minute to get 95% coverage instead of 75% coverage in 30 minutes.