Here's a happy cable card story.
After getting, my S3 to work flawlessly on Comcast, I decided to try another cable card install, this time with Fios TV. The Fios rep had to hit each card 4 or 5 times, but it worked. Both cable card installs, Comcast and Fios, went really well. For both installers, it was their first Tivo install.
And with Fios, I get EVERY movie channel (Only had HBO, Cinemax, and Starz on Comcast) and 3 more digital boxes for $37 less a month! It was definitely worth the risk of a 2nd cable card install. More HD movie channels for my S3! I'm a happy camper!