Top critical review
Can not handle carpet well - thinks the brush is jammed after 20 minutes.
10 January 2019
I would have given this 5 stars, except it seems to have a problem with carpet where after running for almost exactly 20 minutes, it will give an error saying the main brush is jammed (do a google search for RoboRock S50 main brush is blocked and you will quickly find lots of discussion on this, it seems to be a common problem). I am guessing the brush motor overheats on carpet, which also happens when it is jammed.
I did eventually find a work around using the home automation in the app to cause it start and stop several times each day, preventing it from ever running more than 20 minutes, so now it completes without stopping due to this error.
Other than that I am impressed. Picks up cat hair really well due to the brush, maps the floor and carefully cleans each section just once. Does struggle a little with small heavier bits of dirt (in our case kittly litter, which our cat manages to get everywhere), but after several passes it tends to eventually get it.
App that comes from it asks for too many permissions on android (why does it need to read my internal storage?), but if you deny the permissions it seems to work just fine (apart from nagging you).