I already have a 2nd receiver for the upstairs tv in my home, but I am considering a dvr to replace the downstairs tv. Would I be wiser to choose the 522 or the 510? I would not use tv2 since it only produces mono audio, and I presently have stereo with the 2nd receiver. Other than being able to record to different programs, what other advantage does the 522 have over the 510? I have the Dish 500 system, would I even be able to connect the 522 since I already have the 2nd feed running to the upstairs receiver?