I buy the unit base on many positive review on Amazon . it do take cox cable a few reset attempt for they system to see the modem -lrb- 20 minute -rrb- . they be almost at a point of give up and send a tech out . I do not notice any speed increase by upgrade from DOCSIS 2 to DOCSIS 3 . I have not log into the modem interface 192.168.100.1 to see if the same error on the old modem be also show up on the new unit . Terry