Thought some of the issue is that LFE is made for movies, it's an "effects" channel. Some decoders do not do bass with music properly?
For me using LFE I can tell there are subs in use (2 stacked), and constantly messing with the bass levels, as some sources have almost no bass, and others want to knock things off the walls.
Moving to speaker level inputs, one I now have stereo bass (not sure how important that is) my subs have been set it and forget it. If I want more or less bass I just move my bass knob on my pre-amp, I almost never touch it.
For my system, hi-level inputs sounds more blended, it's more even, my subs disappear along with my speakers. They sound more cohesive, in synergy. Plus they are easier to setup over LFE.
For me hi-level feels more analog, LFE is more digital. Think in the end it's all gear and setup dependent.

