When deciding on a sink, I was dead set on a Shaw's, since I can't stand stainless. Then I found this forum and started to read the horror stories, so Shaw's was out. Then I tried the cast iron Kohler, but it was shipped to me cracked. So, I started to look at other options.... found mine on e-bay.

My sink has a soapstone bottom - the sides are cararra marble. I love the soapstone base as nothing will stain it and it has a nice softness to it. The water also makes a nice sound when it hits it, and there is not that tinny sound that the cheap old stainless one I had, made. Others have talked about dropping glasses in theirs and the breakage. I haven't had that problem, but have dropped my cast iron skillet in it without any problems. The outer edge of my sink is inlaid soapstone, so I had a bit of a fear of dinging and scratching that area. So far, I haven't noticed anything there and overall have been immensely happy with my sink.

Soapstone will eventually turn black, and I'm not sure if that is true with every kind of soapstone. However, if that is the case, the sink may become the focal point based on your other colors. That is the only thing that I can think may change your mind. Otherwise your choices sound beautiful.

Be sure to check out Sabjimata's beautiful kitchen with her amazing and humongous soapstone sink.
It makes you want to dive right in and start scrubbing pans and pots.
You can read about her soapstone sink's voyage from Hackensack to Florida on this blog at this link.

Here is a link that might be useful: Sabjimata's soapstone sink and blog

I cannot speak to aesthetics, which I think you were asking about, but think I would love a soapstone sink.

However, it sounds to me like you are mainly seeking an alternative to stainless or fireclay. Many people here report LOVING silgranit sinks. I think this would give you similar aesthetics to a soapstone sink, but perhaps with some advantages. Have you considered them?