I don't know why people bash 'Grail' so much. I really liked it. Same for 'Deathwalker'. It gave us incite into the first four Babylon stations in a different way. And in an athiest-high environment of sci-fi it was nice to see a man searching for the "Holy Grail".
More like an agnostic-high environment, to be technical. I didn't care for the episode because it was badly directed (due to the director being fired from his consulting producer gig before shooting), it relied on yet another thug downbelow, and it wasted David Warner in a role that wasn't memorable nor contributed to the overall arc. Outside of Star Trek V: The Final Frontier, Warner had much better material on Star Trek.