You folks seem to be using your DVR wrong. I frequently record two other shows while watching a third.
First, I doubt that you need an actual second TV, but the setting for dual sets is required. I also have an over the air antennae that is run through mine, which is probably most of the TV that most of us watch anyway.
Depending on the channel, and other settings, sometimes I need to go to My Recordings and start the program over, and that will release the DVR to change channels, but still record the program itself. I'm pleased.
Product or Service Mentioned: Dish Network Receiver.