I ditched cable / dish etc. and went strictly OTA + Netflix three years ago and never went back. I've been using my HTPC since then and LOVE IT.
Gotta run to work right now but a few good resources you can google:
Renethx's HTPC Build thread on the AVS Forum (Rene seems to have dropped off the face of the earth two months ago but it has years of accumulated wisdom plus his late 2011 build guide).
Assassin's beginner HTPC guide also on AVS Forum.
PM me if you like; I'm happy to share what wisdom I've learned.
The one thing I can't help with is cable tuners... I use an HDHomeRun to grab OTA signals but I've never messed with the cablecard versions of the tuners.
"If at first you don't succeed, Scream and Leap!"
NAR member 92906