The SD version won't be half as good as your new HD version.
When we upgraded one of our HD DVR's to the Genie in the new Suite, we had to make a decision which one had the best recordings to keep. So we moved the LR HD-DVR to the bedroom (watched all the bedroom taped shows, then deleted) and had them put the new Genie into the LR. I like the ability to store even more shows and tape simultaneously from 2 DVR's.
We tried to get a 3rd Client for the outside TV, but the DTV Tech insisted it wouldn't work. So he canceled that part off our order.
Fast Forward to a few weeks ago, we had to get a Tech out to see why we couldn't get local channels. Also had the DTV Tech install the wireless Client to our Genie and a bridge picks up the HD signal to the outside TV. Finally a perfect picture on the outside TV instead of the fuzzy one we tried to get with a DirecTV splitter only.