Just wanted to add that the 'center' and 'LFE' channel do contain information. Both channels just need to be normalized in sound editing software, because they're very very quiet.
For instance, on 'Material Girl' the center channel has the male background vocals and guitar, a bit more dry than on the surround channels. Even on the tracks that aren't true surround (like Borderline) the LFE channel has subwoofer into.