You wouldn't cover a wedding or an assignment with one camera body? You couldn't use that excuse that these bodies hardly fail if something were to happen during their "hopefully" once in a lifetime moment. Having the same kind of backup body is helpful and most preferred in many ways but the 7d series makes a very nice backup body to the 1dx series , shaving some weight off the kit.Again, I was asking specifically how many times a 1 series body had failed on the poster. Obviously they do fail, but as Don points out even more modest models fail remarkable infrequently, my point was most people here (forum and gear junkies) 'justify' a second body to themselves because of this strange 'back up' meme that in reality isn't generally justified. Yes there are trips any of us might make once, or maybe many times, in a lifetime where a spare or taking our older body makes sense, but that isn't particularly common.
How can anybody argue with that simple fact?