I don't have any visuals for you, but I've owned both. They're very different to me. Leaving weight aside, the highly polished SS is a very different "color" than the aluminum. That should be obvious, but to me the difference is much greater in real life than on a webpage or even in an Apple store. I don't have a strong preference, but you might.
Another difference is that the highly polished SS tends to somewhat disappear visually (again, my opinion, YMMV) on my wrist. The aluminum is visible as what it is.
There's another very subjective visual issue. Some people feel the SS connotes better "quality" than aluminum. I suppose that might be right, but as someone who wears $10-$20K watches, there is no Apple Watch that really gets into the "quality watch" range. To me (YMMV) it's a short-lived (2-3 years max for most owners) tech wearable. And resale value of the SS versions is not proportionate to the aluminum Sport and Nike models as a percentage of original purchase price - FWIW.
You might have to actually buy and be comfortable with returning one of the aluminum versions in order to really get a feeling for how it works for you. Weight, color and visibility are surprisingly different.
