Don't be so sure, I had a free HR20 and I sent mine back. It was barely passable as a receiver alone, much less a DVR. Missed recordings, incomplete guide data, slow as a brick, no switching between tuners, I knew it was not for my household when my WIFE said it had to go, and she doesn't know jack about electronics.
All that being said, I don't really care if it says TIVO on the front panel, I want it to work. We TIVO lovers get accused of being TIVO lovers exclusively, when, in my experience, if we had a DVR that WORKED as good as a TIVO did for us we'd be happy. The HR20 is NOT that solution. The HR20 is what D* chose to use, and if you have to have D*, the HR20/HR21 is what you will get, so you might as well like it, because you have no other choice. That's my problem. No choice. Given a choice between a MPEG4 TIVO and a HR20 the HR20 would be left in the dust in short order, IMO. . . l
I've had both, an HR10-250 (one of the first adopters) and now an HR20-700.
Both were good units, but I'd give the edge on performance to the HR20-700 in terms of no crashes, tuners firing on time, reboots, etc, etc..
Others may disagree (that's your right) but that's my experience over several years with both units.