A:AnswerThe 3930R is the current model of Roku Express. There are other models available from Roku currently but for the Express the 3930R is the newest one available.
A:AnswerMany Roku models, including the Roku Express, can replace the Comcast cable box. All you have to do is to install the Xfinity app on Roku. The app performs the function of the Comcast cable box. You can do a search online for "Roku Comcast", and you will see many references on how you can set that up. I have 5 Roku boxes around the house with the Xfinity app installed.