Does your apartment lease require that you use Comcast's hardware? When I signed up for Xfinity years ago I wanted to use my own hardware (NetGear cable modem, Buffalo Airstation with DD-WRT). I forget now whether I had to walk through the activation over the phone with a tech - I vaguely recall having to provide some information about the modem, which was one of the models listed as supported on their use-your-own-hardware web page - but the whole thing was easy.

Other people have mentioned that not using Comcast's stuff means that certain features won't be available, but I don't care. I don't have huge bandwidth needs, for instance.