First bought my Roomba Discovery a week or so after this last Xmas.
After a bit of use the first unit had problems charging. iRobot support sent out a new charger, then a new battery, and finally replaced the Roomba itself. The support folks were pleasant and efficient, though I’d rather talk to them less often.
The replacement Roomba ran for a couple months, then got a little too quiet - the brushes had stopped spinning, and the unit wasn’t picking up much. This time it took a bit longer to get a replacement Roomba.
The second replacement Roomba lasted longer, but has started making some very odd noises.
I have a dog (medium-sized dog, medium length hair) who sheds, so the Roomba gets run a few times every day, emptied once a day, and the brushes cleaned at least once a week. As it turns out, this isn’t enough. A few weeks ago I noticed that the bearings seemed a little stiff, so I took off the little yellow plastic bits with the brass bearings - and found the space behind was completely jammed with pet hair!
I’ve not tried to disassemble the Roomba itself, but I’m guessing hair as worked it’s way into other unsealed mechanisms, and is working similar mischief - and is the cause of the odd noises.
Despite all the above misadventures, I do like the job the Roomba does. If you don’t have pets (with hair) then the Roomba might well be reasonably reliable. While I think many aspects of the Roomba design are quite clever, the Roomba badly needs a redesign so as not to be so easily destroyed by simple pet hair.