If you are building a house and is looking for an alternative to a downspout, then I highly recommend that you put a rain chain at each of the corners of your gutter. Rain chains are widely used in Japan. They are usually put there to present a water feature out of rainwater that comes down from the gutter.
The first time I encountered copper rain chains was in the house where my sister used to live. At the bottom of the garden rain chains were big clay jars that serve as rain barrels that collect rainwater for gardening purposes. And then whenever it rains, the water guttering from the roof flows beautifully downwards like a subtle fountain. I think it's a lovely idea especially if you have like sort of atrium or a garden within your house.