I have DirecTV & TWC. I prefer TWC for watching most everything. Their guide system works so much better, and its much easier to find the channels you're looking for. The only reason I keep DirecTV is for sports (NFL, NBA, ticket). As far as HD or non-HD (SD) you'll be able to watch either. They do provide a different cable box depending on whether you want HD or not though, so only your HD boxes will get HD channels.