It makes sense comparing iRobot Roomba 980 vs iRobot Roomba S9 because they both are able to give some premium features. Based on our rating, Roomba 980 has the overall rating of 8.7 out of 10 versus 9 for Roomba S9.
A noticeable difference between two models is the size, which is 53.5 x 14/21 x 17 x 5.5 (D x H) cm/inches for the Roomba 980 and 30.9 x 8.8/12.2 x 3.5 (D x H) cm/inches for the Roomba S9. The weight of the Roomba 980 is 6/13.3 kg/lbs, and for the Roomba S9 it is 3.6/8.1 kg/lbs.
The iRobot Roomba S9 is better robot vacuums in this comparison. Check iRobot Roomba S9 price