I did my first MPEG4 HD comparison a few months back:
http://dbstalk.com/showthread.php?t=118154
This time I used the same method, only this time I have both services so the comparison was live HD shows during prime time (did not touch SD ones at all), but the tested channels expanded to FOODHD, USAHD, UnivHD, NatGeoHD, TennisHD, MHD, SmithHD, HDNet, TNTHD, SciFiHD and ScienceHD. The test result is about the same as the first time, E* HDs showed more compression related artifacts but only in close inspection, at a normal viewing distance one should not see the differece in PQ.
I could not do A/B comparision for the premium channels since I now have HBO, Starz and Cinemax from E* and Showtime from D*. But both E* and D* premium HDs have been free of compression related issues and very comparable in PQ.
Starz HDs continue to have the best HD PQ, with HBO and Showtime next, and Cinemax sometimes a little lacking but they all are great in HD viewing experience. I actaully preferred HBO and Showtime's more film like products as to the more video like Starz look.
This time I got an E* 722 because "622s are discontinued" according to the installer. I also am grandfathered in with the HD Absolute which was why I decided to add E* along side of my full D* service. The 722 was installed yesterday.
The E* 722 runs much hotter than the D* HR21, the guide on E* is faster and easier to use, but D* guide has a much better HD channel grouping. D*'s VOD offering is also much more robust than the E* 722 "online" VOD.