Roomba - great concept, but...

I love the Roomba. But it appears that instead of eliminating labor as it promises, it merely redirects it. Instead of vacuuming, you spend time (admittedly less) repairing it. I have two. The second one, model Roomba 4150, had a ground down spur gear or drive gear. This prevents the vacuum beater and sweeper (Quidditch, anyone) from actually rotating, with the added side benefit of some really loud grinding noise. Replacement gears are about $30. Repairs are executable (I had it apart and back together to find the problem). Now just need to decide if it is worth the money. Right now, I'm voting not.