I post my Neato reviews occasionally when it pops up on here, so here goes again. My brother was just asking me how mine's holding up as he's thinking of getting one. Gonna link him, and he may be reading this now. Creeper.
I've owned the Neato XV-12 for just about one year and this past Xmas I received the pet and allergy upgrade which is a new brush and filter, and that essentially makes it the same as the model sold here. I lived in a 2 bedroom 1 story duplex, just over 1000SF, and rarely had any problems. When we first got it, I ran it a few times in only a few days because we didn't vacuum too often, so the bin filled up each time. Since then, I keep it on a once a week schedule, and the dust bin is still full each time.
After a short while, you learn to keep things off the floor before it's going to run (bonus; your home is less cluttered) and any other little tricks you can do to make its life easier. We found that it got stuck between the toilet and the bathtub. A simple fix would've been to just put something over there like a trash can or toilet brush, but we just closed the bathroom door instead. I also tuck the bed skirt under the mattress so it's sure to get under the bed OR so it doesn't get under there and then think it can't get out.
I love that it takes into account what a "room" is, and will do that room first before moving on to the next. As mentioned before, it does the perimeter of the room, then does parallel lines up and down the rest of the room, so you end up with nice straight vacuum lines. I have fairly plush carpet, vinyl in the foyer, kitchen and bathroom, and a fairly large near-shag-level area rug. It runs a little slower on the rug, but is not a problem at all, and I figure that only helps it clean a little deeper. Doesn't have any problem with thresholds between the types of floors for the most part. Occasionally it will have a little difficulty, but it backs up and tries to go at it at an angle and always succeeds.
It usually returns to base to charge before doing the whole place, and very rarely has it gotten lost. I'll come home once in a while to find it in the middle of the room or worse, 2' from the base. But I'd say at least 90% of the time I come home to find it back at base. I like to have it set for Mondays, right about the time I wake up, as it's an excellent alarm, and I'm getting ready for work or not at home when it's running (as opposed to trying to watch TV etc).
I have a cat and it picks up fur and litter well. I also had a girlfriend living with me for a long while who had long hair and I did have to take out the roller and cut hair off of it just about every week, which is easy enough to do. We're no longer together and now I almost never have to clear the roller (score!). And you do of course have to empty the bin after every run/before the next run.
From what I've always read, it sounds like Neato is pretty good with their customer service if any issues arise. I haven't had any yet. I probably have more I could say about it. Happy to answer any questions.
Get it, you won't regret it.