3) I hear lots of people say the 722 is better than the HR21. I haven't heard anyone say the HR21 is better than the 722.
DirecTV HR20 (DirecTV Plus HD DVR) Digital Video Recorder (DVR) reviews - CNET Reviews
Can 315 end user reviews be wrong?
I recently switched in reverse to Dish. Two observations. First, Direc and Dish have nearly as much HD programming as each other. With OTA, the count is really about the same. Second, the HR20/21 have the same software, but the HR20 has more connections than the HR21 and the software is a work in progress. TiVo (8 year ownership) is comparable to ViP722 in terms of usability. Both have advantages over the other, so it is tough to complain about either unit. I made arrangements to return the HR20 after questioning Direc Technical Support over advertised functions that did not work, namely Search and Auto record. D* Tech Support said, "Since this is your first DVR, you will just have to learn to deal with it." D* admitted their DVR does not function as advertised.
Reader's Digest form: Content is equal. DVR advantage Dish.