For me, Music Explorer is a means for music discovery. Artists who are similar to artists in my library, what else an artist may have released that's not part of my library yet, track previews of the aforementioned, etc. It's meant (at least in my mind) to put the music in your library in context with the rest of the world of music that's out there and help you explore it. Music. Explorer.
I don't use it much because it, by design and purpose, lacks function for what I mostly do, which is manage my own library. I spend most of my time in the Library Explorer (i.e. "Main Panel") that you've been directed to twice now as the right tool for what you're looking to accomplish.
I'm, again, along with psychoadept it seems, struggling to understand what it is that you think you'd be missing out on by using the Library Main Panel. "Doesn't cut it" or "Doesn't come close" doesn't really describe what you feel like you're unable to get there, and without knowing that bit of information we're kind of at a disadvantage as far as finding ways to help.