If they didn't drop the price down to China made price then it matters for sure. I just use the grates that came in my old webers, so I have no input on SS grates. But when I was looking into building my own flat top, I had read that you don't want to use stainless because it doesn't season like cast iron or mild steel does.
Does anyone offer a non-plated mild steel grate? I think thats what I would want.
I also have the grate out of my char-griller premium kettle, it has the removable center piece, and it has thick bars coated with porcelain.