I bought an original Apple Watch in 2015 in Stainless - Silver. I am upgrading and I own a Link Bracelet knockoff that is quite nice and a Milanese Loop knockoff that is ok, as well as genuine Apple Leather Loop in dark Blue, a Black Sport band that it came with and a couple knockoff Nike+ bands. I debated right up until ordering last night whether to get a new Stainless, a Space Black Stainless, or a Nike+ in Space Grey.
1. Not a fan of the aluminum. I like the weight of the stainless.
2. Not a fan of the space grey. You can see it isn't black. The Space Black match the screen and looks seamless.
3. I liked the idea of the Nike+ though I am not a runner due to the special watch faces.
4. But the aluminum watches (silver or space grey) are not color matches to the metal bands I have or you can get. (Though Juuk makes a grey metal band that is Tag Heuer like and looks good and matches the space grey).
5. I don't wear my Link or Milanese much and primarily wear the sport and leather.
So I opted for the Space Black Stainless Steel because:
1. I can wear the black sport, probably get a Product Red sport that will look great with it, and I may get either a white or a black Apple Nike band for it too.
2. I may sell my Link and Milanese with the S0 Stainless or see if they work with the SBSS. Likely not. Probably get rid of them.
Another reason I went for the SBSS is that the screen is more edge to edge and so you won't see as much of the case. I think this will make the regular stainless case stand out less and the seamlessness of the SB case fit the watch better.
Lastly, I've heard the DLC coating on the SB holds up very well though in 3+ years I have very little in the way of marks on my Silver Stainless and I have never polished it. Maybe they are there and I just don't see them.