to establish some background , I have cox hsus and have be use this modem for about a week . I buy this modem to replace a trusty 6 year old Scientific Atlanta DOCSIS 2.0 modem that bite the dust . I really like how the sb6121 keep my speed constant day and night . the 4x4 channel bonding help alleviate the peak time slow downs associate with a busy\/overcrowded node . on the flip side , channel bonding also help you isp enforce the cap on you subscribe internet speed . on my old modem , I would often see 30 Mbps down -lrb- my advertised speed w\/powerboost be 20 mbp -rrb- . speed test indicate my speed be now lock at 20-20 .5 mbp throughout the day . yet interestingly , I be get 15 mbp up ; -lrb- more than quadruple the speed advertise for my connection tier -rrb- ! I guess cox be not enforce upstream speed cap that well at the moment . I love how Motorola let user access the full modem signal and log at 192.168.100.1 . activate the unit be a breeze - simply call cox and read they the modem MAC ID and customer s\/n from the bottom of the box the modem come in . I will post a update review after I have play with and test the modem for a few month .