The makers of the Husqvarna 430X claim that it will produce the perfectly mowed lawn and YouTube videos, not all of them from the robo-mower's manufacturers, go a long way to proving their point. The Husqvarna works with a boundary wire, which you have to place along the edges of those portions of the lawn you want mowed, so that the mower doesn't wander astray into the neighbor's yard or cut down your carefully cultivated bed of flowers. When the batteries get low it can find its way back to the charger via a radio signal, but should that fail it can trace the guide wire back to its point of origin, which is always the charger.
The unit is sleek looking, like a sports car with blades. Used regularly, it produces a remarkably even looking lawn, without visible clippings, and is inexpensive to run, the equivalent of an electric car when compared to internal-combustion-engine-burning mowers. It's quiet, which is a plus, and will make you popular with our neighbors. (Nobody enjoys waking up on Sunday morning to the sound of somebody mowing the lawn next door.) It increases the amount of mowing it does depending on the weather, with more cutting activity during the rainy season, when grass grows faster, than during droughts, when the lawn just needs the occasional trim. (To deal with the drought, you might want to check the Smart Sprinklers section of this site.)
The Husqvarna 430X is expensive, so the sports car analogy doesn't apply just to its looks. Be prepared to shell out a substantial portion of your credit line to buy one or look for a good used one. The units are reportedly durable and should be good for a run around a second lawn. If you'd like a mower in a less pricey zone, take a look at the Milagrow RoboTiger 2.0, the E.Zicom Evo 3500 or the Worx Landroid, though they may not produce as evenly cut a lawn.
I have it mowing in the middle of the night so that when I wake up every morning my grass looks the same as it did the day before. I can say that it's been a life changer.
After the first week, my lawn looked ok. After two weeks, it looked much better. After a month, it looked fantastic.