We have had the first contact with vacuum cleaner robots for friends, an iRobot from the 500 series. Our friends were very happy, so I have plenty to internet research chose the iRobot 780 - also because return is not a problem with dissatisfaction at Amazon. Delivery as usual quickly (2 days after ordering there), packaging very good, unpacked device and loaded only once overnight. The next day the first use, in any room often -as recommended- the presence control. We had read previously, the iRobot would in dark soil problems, he thought, there is an abyss ... We have a black stone floor, on bright Carpets- an extreme situation for the optical sensors so! I will be very brief: No problems with the black pieces, transitions to carpets and back without jerking, brakes on stairs immediately, not "thundering" against dark furniture. Cleaning: We are very satisfied. Have a long-haired cat and previously a Miele vacuum cleaner Cats and Dogs. What the small iRobot receives at each cleaning - as if we had for weeks sucked dust. Cat hair is not a problem, all the way he takes music to birch leaf size without problems, the size of the receiver than enough for 80 square meters. With the lighthouses a meaningful navigate in 3 rooms is possible, so that iRobot still finds the charging socket - is also necessary. Unfortunately, the battery does not last - as we read in some reports - 3 hours but only just over 1 hour, but that's no problem: He travels back and charges, dressing in the same place, where he had left off. Another advantage is that it will last even under beds and cupboards clean, if they are not too deep. For cables we have experienced the way (4 weeks of use) no disturbances. If iRobot runs over a cable, it has a developed mechanism, which so far, can resurface perk himself under the bed, where speaker cable, power cable, etc. are manifold every time. Cleaning the unit: I do not understand those who think this is complicated ... Daily the dust cup is emptied, 1x a week cleaned the brush. Empty dust cup Duration: 15 sec (inclusive way to the trash can), continuous brush cleaning: about 2 min. The bag change in which Miele is much more complicated, takes more time, even if it is only necessary every few weeks. Conclusion: A thoroughly successful enrichment of our budget, we bought spare time. Based on this positive experience, we decided to create a robot for lawn mowing next spring ...