Majack,
The point is that currently, for all providers DirectTV, Dish and VOOM there are not any DVR products that record Analog OTA (or cable) as well as the satellite signal. The 921 does have an OTA tunner, but is not equiped with an encoder so it only records the Digital OTA signals.
The only solution at this time is one of the "stand-alone" TIVO units (not any of the Direct TIVO either). Personally, these stand alone devices are going to become obsolte at some point when all OTA are digital, since the stand alone TIVO units only support the Analog signals (at this time).
Hope that helps. Guess my long winded answer is that changing from Dish to another provider isn't going to solve this problem for you (in case that was a thought in the back of your mind).
In any case, enjoy your existing DVR.