Got the Neato XV11 + Pet Kit from Groupon a month or two back. Loving it. Picks up a ridiculous amount of pet hair, even after doing a cleaning with a Dyson.
All the Neato's are pretty much the same, the only major difference aside from color is the Brush/Filter used. So a XV11 + Pet Kit = XV21. Pet kit is totally worth it, especially for the pet brush.
Works best if you have an uncluttered space for it to clean. No random stuff on the ground, pet toys, cords, etc.
If you get it, let it charge for about 24 hours. It has to learn the battery capacity over time, so give it about ~10 dockings before deciding the battery is wack and calling support. When the battery works itself out, you should get at least 30 min on carpets, 45 on hardwood.
You can reuse the filters and clean the Neato with a regular vacuum or handvac. Also be sure to vacuum the brush belt motor area, it likes to attract pet hair. It might seem like a lot initially, but it goes down after a week as the Neato clears out any areas with built up pet hair that you otherwise missed.
It's also really loud. like a regular vacuum cleaner loud.
Does hair end up wrapped around the pet brush?