My son uses one, got it about 4 years ago. He does use it, but I can't see how it saves time and effort as you have to prepare the room first and it doesn't hold much before it beeps and wants emptying. Youngest grandson is terrified of it. He has a normal vac as well for a more thorough cleaning.
Obviously,being circular, there are edge areas which occasionally have to be covered with a conventional cleaner, but but only very occasionally (like once since February).
Our method is that for a routine clean we switch it on when we go out and it does its thing for an hour or so. Every so often, for a deeper clean, we prepare the room a little, make sure all wires are out of the way, and there are clear paths.
Because the dust compartment is small we find little (like one or two rooms at a time, rather than the whole floor) and often the best way.
Much of the criticism of these cleaners is due to over expectation.
If you have a dining room table with four chairs tucked in around it do not expect a very good clean under the table!
Used it earlier today and if it had broken down I would have already had a new one on order from Amazon.
The one I have will run for well over an hour before docking itself for a re-charge (yes, that's automatic too) and even in a small No 3 bedroom the algorithm keeps it covering the floor for at least half an hour, longer if it's dirty (it can sense that too, and does a spiral "spot clean" and lights an indicator so that you know it is still cleaning and not just stuck).
It brings the carpet up better than Miele, but not as good as a Dyson.
However, the Dyson is a damned sight harder to carry up and down stairs if you're disabled!
I used Amazon, not necessarily the cheapest, but if you're unsure of ultimate satisfaction then it has by far and away the best returns policy and system!
Get the one that automatically docks itself, empty it every time, including hair from around the beater, and make sure that it puts itself on charge each time (it plays a natty little warble to let you know it's docked).