The iRobot Roomba S9plus vs iRobot Roomba 671 comparison shows that these robot vacuums have some important differences and common features. Based on our rating, Roomba S9plus has the overall rating of 8.5 out of 10 versus 6.7 for Roomba 671.
A noticeable difference between two models is the size, which is 30.9 x 8.8/12.2 x 3.5 (D x H) cm/inches for the Roomba S9plus and 34 x 8.8/13.4 x 3.5 (D x H) cm/inches for the Roomba 671. The weight of the Roomba S9plus is 3.6/8.1 kg/lbs, and for the Roomba 671 it is 2.2/5 kg/lbs.
The iRobot Roomba S9plus is better robot vacuum in this comparison. Check iRobot Roomba S9plus price