I have the iRobot 980 and was looking forward to getting the S9+ as an upgrade to my current unit. This turned out to be a downgrade in my opinion. The S9+ RARELY makes it back to its base at the end of a cleaning cycle. My home floor plan is very simple and I always move obstacles that I think the Roomba will have trouble with but the S9 constantly gets stuck on nothing and i'm having to carry it back to base 8/10 times. My Roomba 980 never gets stuck and always makes it back to base. The S9 seems to be a much more powerful vacuum however and when it does make it through a cleaning cycle my floors look and feel amazing, especially the carpets!