Fish being "Better" is a matter of personal opinon. Like if i said i hada 55gal and i didn't want to stock it with plain livebearers or tetras because cichlids are "better". Sure to some people...
And i'm sure its hard to keep that water crystal clear reguardless. Plus its more natural the way it is.
Heh, well when you're there and looking - its gotta be pretty cool watching big huge lakey fish hovering. Although, it'd feel more like a constant trip to the aquarium. And I've noticed that the big tanks at the aquarium are never very clean-looking.
Hmm... how about fancy goldfish in a tank like that? Not even koi, just big round clumsy goldies