OTA is not something DirecTV is doing much to improve at this point. No update to the several year old AM21 (N just changed from glossy to matte plastic). They had scanning in the Genie software and removed it (customer's call about channels that have no guide data, so it is just easier for DirecTV to remove than explain why some channels don't have guide data).
HR44 is a much smaller box, and different power adapter. Their solution to that was to add a plastic cap the the AM21 box to cover the different power cord when using it with an HR44 (or H25).
Still only two local markets, zip code based, and no channel updates (except just a few) in years now as for guide data.
Needless to say, support OTA is not much of a priority for Directv.