Back to the present, and having looked at all the photos of the real Fallingwater in the instruction booklet, I've now realized what the problem I have with the set is: the building is amazing, but the environment ... is just boring. And not at all realistic. There are tan bricks everywhere when the stone around the house is grey. The "trees" are short, straight, really dark, and spaced evenly around the house, when the trees around the real house are huge, bright, and tower over Fallingwater itself.
And then I realized that there was a huge irony in the fact that the booklet that comes with the set has a ton of quotes about how Fallingwater is great because of how it interacts seamlessly with the beauty of the natural woodland environment around it... and yet the set has this utterly boring, unrealistic environment.
And I noticed shortly after that that it would be really, really easy to make all sorts of big, leafy, brightly-colored trees out of Lego to surround the model of the house. Just use a bunch of these pieces and you'll have some fantastic, to-scale trees. And make the base of the set grey instead of tan. And maybe throw in some clear aquamarine pieces under the clear tiles in the river, just to brighten it up some.
Yeah. If I had the boatload of grey bricks necessary to do this, I would. But alas, I don't.
Also: thanks to Tufi and Janus and one volume thereof I may now be addicted to Scott Pilgrim. Need to read more...