Heck, I think Chris K. is watching us from the clouds. Here's what he has to say on the issue of lowering the LPF from 120 Hz to 80 Hz. " If you feel like remixing (some call it shaping...) the content in the LFE track then sure. So, preference vs reference again. But if you want to hear it the way it was mixed then you should leave it at 120 Hz (or higher where it won't be in the way)."
A candidate for the FAQ, eh?
Source: Audyssey Tech Talk at FB.