You will get HD TV that you don't get with the Comcast's basic cable
without paying extra.
Yes, You will receive the sub-channels that Comcast does
not always broadcast with their basic channel package.
Yes, you get 17+ HD channels over the air.
Yes, you get over a hundred digital channels to watch.
Yes, you get all of the major networks.
Yes, Your digital HD TV is all the equipment you need
after installation of a quality
Yes, DVRs, such at FireTV, are available
and they come with with channel guides just like cable.