Here is the way I have my system setup to get maximum flexibility with only one 622:
-My 622 is in the living room, and is connected to a Component Video distribution box ($50 from Radio Shack). One component cable goes from the distribution box to my living room TV. (The LR TV doesn't have HDMI - if it did, I wouldn't need the distribution box.)
-My OTA antenna has a splitter. One feed goes to the 622, one goes to the living room TV, and one goes to the rest of the house.
-The house output from the OTA antenna is combined with a joiner (from Stark Electronics - online) to the coax output of the 622. This goes out to the other TV's in my house, including the HD TV in the bedroom.
-A second component video line from the distribution box also goes to the HD TV in the bedroom. (75ft component video/audio cable from Monoprice.com).
This gives me the following options for the HDTV in the bedroom:
1) Watch any over-the-air channel of my choice using my OTA antenna and the TV's built in digital tuner.
2) Watch the same HDTV program from Dish network that is being viewed on the living room TV via the Component video input.
3) Watch a different program from Dish network using the TV 2 output over the coax cable (on my TV, it's channel 60), if I have the 622 set for dual mode. (Of course this is SD only.)
4) Since the Living Room TV has its own digital tuner and OTA antenna feed, I could also watch an OTA channel in the living room, while allowing the bedroom TV to have full control of the 622 (in single mode.)
Of course I understand all this. I'm not claiming anyone else in my household does!