I've used Comcast and CenturyLink. I would say CenturyLink, while not perfect, is miles better than Comcast. I pay $70 for gigabit: symmetric, no data cap, never had an outage, monthly contract. Only had to deal with support once when I was returning their router.
Comcast had shitty uploads, long contracts, data caps, outages, shitty support, would call me randomly trying to sell me TV plans. I had a Comcast tech cut random wires in the network closet for my building and gave me an outage when I was using Starry, they're beyond horrible.
Not surprisingly, North Korea's Red Star OS has a closed source fork of KDE.