I'm happy with it thus far, it's able to deliver at/above the contracted speeds, which is all it really needs to do. Using a TP-Link router from my Charter days with it.That's the one I was just looking at on Best Buy. I have a Netgear dual band gigabit router that's been idle since the Xfinity box arrived.
Not sure how involved setting the modem up is, since I paid for a Comcast tech to come out (I knew that they would have to run new cable to this house, plus change bad coax plugs).