Comcast didn't charge me a deposit for a cablecard here in Denver. I'm running a windows media center Ceton cablecard-based setup using a central PC and several media center extenders to feed content to tvs. While the media center extenders I use have been discontinued, one can also use xbox's as extenders. I think it best to wire these via ethernet, but others have had luck operating extenders wirelessly. As far as areas where HTPCs are not an option, I'm about to pull the trigger on a hdplex fanless case. Combined with a ssd, this would result in a silent computer without moving parts. Both the Ceton and the HDHomerun prime allow for access to the cablecard tuner from a remote computer. This would allow me to keep my big tower as the hub of my htpc setup and use small, fanless pcs to remotely access the cablecard and central content.
The ceton allows me to record/watch 4 shows at a time, and works quite well on my older dell quadcore xps 420 "server" for high definition tv playback/recording.