The Arris Surfboard S33 is recommended as the top Xfinity-compatible modem for its 2.5 Gbps performance, while the Arris S34 and Netgear Nighthawk CM3000 are better suited for faster, "Next Gen" upload speeds. For optimal performance, users should select a DOCSIS 3.1 modem, with the Hitron CODA56 cited as a strong, high-value alternative. Find a complete breakdown of recommended modems at CableTV.com .