There are several reasons to consider keeping OTA. First, you get all of the subchannels that you do not get through DirecTV. Second, some people feel the ota HD transmission is higher quality than that through satellite. Third, OTA remains during weather outages that block the satellite signal.
I can vouch for the "better quality" It isn't real noticeable, but OTA does look a little cleaner and color vibrant.....a little.
Can the HR20 receive all the subchannels? Edit: Didn't see Bonscott's pos. You said it too! I need to slow my reading down!
In regards to the before mentioned quality, will that diminish if you pipe the OTA through the HR20? Is it better just to let the TV's tuner handle em?