Hole-in-the-wall, out-of-the-way, lowkey or under-the-radar all mean one thing when it comes to restaurants, you should probably try it as soon as you can.
I'd like to state for the record that I've never met a burger that I didn't enjoy so this new internet claim that there's one Missouri burger joint you need to avoid does not apply to me. But, just maybe you'll need to consider their advice.
I have nothing against Missouri's big cities. Have been to St. Louis and Kansas City a million times in my life and that's only a slight exaggeration. But, if you crave the best 'classic' diner in the state, you don't need to deal with the massive traffic jams in Missouri's metros based on a brand new ranking.