First of all I have to say that we used to be very skeptical about vacuum cleaner robots - I couldn't imagine those things could do a good job. That was a year and a half ago and now we have two.
In our house, vacuuming is necessary almost every day and we don't always have enough time for that. So I bought a robot last year. That was the Roomba 980, iRobot's top model in mid-2018.
Once in the house I was very pleasantly surprised at how much dust that thing picked up from the floor. With kids and cats you can expect a lot of dust and hair all over the floor, but as much as the Roomba could get off the floor I didn't think. The coarser mess such as papers, cat litter or handkerchief wads go without any problems. Even whole pens are picked up. ;-)
Eventually there was an almost daily living room/floor work schedule for the Roomba. With a relatively large floor area, that still saved over an hour of manual vacuuming. There is now remarkably less dust on the furniture than before. And then the power consumption is also much less than when using a regular vacuum cleaner. In short, it turned out to be a very good purchase despite its price.
But a few months, 1 problem emerged, the container was full every 1-2 days. The 980's receptacle is not too small, but certainly not large either. But with a full box, the Roomba no longer starts its schedule, and you soon forget to empty that box in advance.
After a year, we looked at the new models i7+ and S9+ with the extra collection container. Opted for the Roomba S9+. As advertised, this one is indeed just a bit better and comes better in the corners. The large collection container on the charging station is certainly a godsend. The only drawback is that its size means that you really have to give the Roomba its own corner in the room or, as with some other people, in a storage room in the hallway (see youtube: "Roomba garage"). You can also easily park the Roomba 980 under a high cupboard.
An advantage and also disadvantage of the S9 is that it must first "learn" the floor/room. The Roomba turns the floor into a digital map. The advantage is that after learning the different rooms/zones of the floor can be named. Then you can then programmed specific parts to suck. This is not possible with the Roomba 980, it simply does everything the thing can come to at that moment.
The disadvantage of "learning" with the S9 is that the entire learning process takes several hours depending on the shape, obstacles and number of square meters of the entire floor. You also have to remove almost all objects that are not always in the same place, such as chairs and/or separate tables. If you don't do this, the spot where a chair or other obstacle stood may be completely ignored. Our cats also kept walking around the new Roomba, which disrupted the learning process. The result was that part of the corridor was not mapped and was therefore not included in the cleaning round. The device "measures" distances between obstacles and a sitting cat in the hallway is often also seen as a permanent obstacle.
Anyway, the entire learning process can take about 3 to 6 rounds (1 to 3 hours), depending on the shape of the rooms, number of fixed obstacles and of course the total number of square meters. The standard method takes the longest: scanning while cleaning - it is faster to use the separate train option.
Once the floor has been mapped, this is more or less permanent. The part where the S9 was not driven during learning is also permanently ignored afterwards. You can provide the map with "no-go" zones, but you cannot supplement/enlarge/correct it. Since the latter is a wish of other i7 and S9 users, I hope that this functionality will eventually be added to the software.
As soon as the created card is correct, the cleaning round goes faster than with the 980, which has to "discover" everything again and again.
Then the cleaning itself. In terms of size, the S9 is slightly narrower and slightly lower, so that it can better be hidden under chairs. Compared to the 980, the S9 has a wider and lower brush. It cleans just a little faster and better. The disadvantage is that the slightly lower position also ensures that the S9 can not or only with difficulty drive up some thresholds and thick carpets. Small thick carpets on smooth floors, if they can slide, can still be moved by a Roomba. So you may have to adjust those places or you should opt for the Roomba i7+ that is a bit higher on its wheels.
The side brush model of the S9 is fine for smooth floors and picks up the (>90º) corners very well, but not with deep-pile floor coverings. The 980 and i7 are just better at that. However, the brushes are replaceable and perhaps there will be a modified version in the future. It is in any case advisable to order an additional package of spare parts: filters, side brushes, etc. Enough choice via the internet.
Then construction. Here, the S9 is slightly less than its predecessors in terms of exterior. Where the Roomba 980 and the i7 have a somewhat thicker edge with rubber bumpers, that is completely missing from the S9. The completely plastic housing has a bit more of a scratching property. And that's more likely to happen if the Roomba is under a heater or cabinet that it just barely fits under. On top of a Roomba there is usually an excellent sensor part and it still wants to snag on low parts.
Incidentally, I have not yet experienced the Roomba scratching/damaging the furniture itself. Of course you should not put down very delicate furniture; for those objects you have to set the no-go zones.
For us, the S9+ is a welcome addition. The S9 now does the ground floor almost daily where most of the dust can be removed. The 980 now does the upstairs a few times a week; bedrooms also have the usual dust nests.
Incidentally, the S9 is also somewhat quieter than the 980. At the weekend, the living room can be cleaned quietly at 7 o'clock in the morning, while sleeping on a floor higher. Only the emptying of the collector makes a lot of noise. However, that only takes about 5-7 seconds, we don't really notice that much when we are at the top.
