be pay for premium inter net service from cox . be not satisfy with video quality . be get download speed of less than 10 mbp with 5 year old Motorola modem , be pay cox for download speed of over 27 mbp . sb6121 now give I download speed up to 32 mbp for same price from cox . make a significant improvement in video quality on computer and Smart tv when watch inter net video from Netflix , YouTube , Apple TV , ect . set up be not difficult , need cox to do its part of set up for new modem . Motorola phone help be excellent if you need it with the modem too .