I have both 129 and 61.5, so I think I can answer this. I did some experimenting with "moving" to get Detroit locals, which are on spotbeams on both of those satellites. Where I am located, I cannot get that spotbeam signal from 61.5 at all, but the 129 spotbeam works most of the time. Unfortunately, when I connected the cable from my 129 LNB to the input port on my 1000.4 EA dish and ran a check switch, the Detroit locals were still only trying to get signal from 61.5, and I could not receive them at all. I had to cover the 61.5 LNB with foil and do a check switch again, completely removing 61.5, before the receiver would recognize that I had signal from 129. I assume that weather-related outages would be treated similarly to a lack of spotbeam signal in a fringe area.
If I remember correctly, the satellite that the receiver uses to try to tune each channel is determined by the guide matrix that is created during the guide download. So, in the case of channels that are duplicated on two or more satellites, the receiver will only look for the one that happened to be detected first during the guide download. The receiver will remain unaware of the duplicates. If you are using an external switch, you may be able to give one satellite priority over the others, by changing the order in which they are hooked up on the switch. In my case, the input port on the LNB takes lower priority than the built-in LNB's, apparently. I did this experiment with a ViP receiver. So, for all I know, the Hopper software could be completely different.
