I had Comcast install 2 cable cards in my HD and everything went well. I subscribe to limited basic for $15.99 month. I had to call more than once to find a CSR who knew the correct price. The first card is free and the second card is $2/month. I have no Comcast boxes and keep basic service for the multiple older analog only TVs in the house. There are several advantages to using cable cards. All the channels are now easily 'tunable' versus being hidden on virtual channels like 100-9. TiVo guide only lists channel information for the virtual channels if cable cards are used. (Something I think TiVo should fix.) All channels are digital so no more gray screen of death which happened twice in 2 weeks. The installer brought 3 cards and the first 2 worked. He had a hand held terminal and wanded the bar code on the card and inserted them 1 at a time. When the TiVo screen came up he enter the information into the terminal and then had me test the card on channels I did not get before. Very smooth and quick and he did not need to make phone calls.