Internet pretty good, cable TV service so-so, cable TV hardware awful.
Had Cox internet+TV in Santa Barbara and Irvine (mainly because they were a monopoly in both locations).
Never had a problem with internet. Fast & reliable.
Live TV service is average, on-demand is ether outrageously expensive or the free stuff is lame. Get a Roku instead. I never use any of the "Contour" features because they don't do much.
Cox's exclusive Cisco receiver is average, the Cisco DVR is loaded with bugs: missed recordings, recordings that can't be played, recordings unplayable over the "Whole Home" network. Their solution? "Unplug the DVR and reboot it". Works about 10% of the time.
Internet: B+
Live TV: C
On Demand: D
Cisco non-DVR receiver: B
Cisco Whole Home DVR: D-
If you're not forced into Cox, consider AT&T Uverse or DirecTV instead.