I think this one is a keeper. We had bad experiences with a Eufy (after several weeks, suddenly didn't like carpet) and a Trifo (didn't complete the job--"Done with my chores! Returning to base." and sometimes couldn't find the charging base). This iRobot i3 seems to be doing what it's supposed to do, and does it pretty well.As was true of the other devices, installation instructions are poor, just a basic start up card. I had to call support to get it to connect to our Wifi. Got the app installed easily, but the i3 was not an option on the connection choices. I chose the j3 because the device pictured looked most like my i3. Turns out I should have chosen "vacuum" which looks like another iRobot model. Once customer support took me there, installation was simple.From there it's a guess on how to work this thing. I eventually found the app has a subsection on how to work the robot. But I had to stumble across it. The robot wants to be sent out without vacuuming to create a "map" of the area. The first map was distorted and odd shaped, of no value. The second try produced a pretty good picture of our 900 sq ft, 3 rooms plus baths. A bunch of lines were lying around the map and I discovered I could move and rotate them to identify separate rooms. After some additional effort, I found i could name the rooms. Great!Strengths of this robot include pretty strong suction. We've had our area vacuumed regularly--it's about 1/2 carpet and 1/2 hard floor--but this robot is sucking up hunks of hair and stuff that we had left behind. (We have a dog.) Another thing I appreciate is unique twin rubber rollers. Our other robots had a single brush and it got tangled with hair and threads quite easily. It's a pain to cut and pick it off. No cutting/picking with rubber!Another good: the robot runs in straight lines, back and forth. It will do part of a room, leave and do another room, and then come back, starting up where it left off. The other robots moved more at random. The iRobot leaves nice straight paths that look like its been vacuumed. It also goes around furniture as closely as it can. Under furniture if there's room. It will circle a table leg and then go off. It has not gotten caught under kitchen table/chairs like others had.iRobot also has not gotten caught on any cables, toys or clothing. The other robots had frequent difficulty with these things. The i3 just avoids them or rolls over them.So overall, we like!The biggest weakness is short battery life. It will go for maybe 90 minutes or a bit less and then have to return to base to charge. After 45 minutes or so, it comes out and gets back to work. Our 900 sq ft seem to require three or even four separate cleans, with charging in between. So a full cleaning even in our small area can take 4 or more hours.It also will stop if the dust bin is full, which is happening quickly as I said. Big start button on the top lights up red; but look on the app for a message. Eventually I got a dust bin full message when there wasn't all that much visible in the bin. Seeing this twice, I also removed, cleaned and replaced the rubber rollers (which had thread and hair curled around both ends) and this seemed to fix it. So Clean Dust Bin can mean empty the bin or clean the whole thing. Somewhere there is a dust bin sensor that I haven't yet found.Rated 4 overall for short battery life.