But keep in mind that if there are HD Locals in your market, then you can record from the OTA tuner and both HD Sat tuners at the same time. So for me, I can record up to 3 HD LIL channels at the same time (Which comes in handy on Thursday nights). The DirectTV HD DVR will only record two programs at the same time if I recall correctly.
The DirecTV receiver can record 3 at a time if the 3rd program is VOD.