Only really been on my wrist for a few hours. I love this watch. You're completely right about the line, and it actually slips out of sight quite easily, when checking your watch. The light plays a bit with the curves and ends up hiding the lines. The whole thing ends up looking like one curved, shiny, blacked out face, and I love that. It looks borderless.
Found out that all watch cases don't have that blocky, G-shock look, so it's actually possible to still have that regular stainless steel look, if you just put on a slim case. The black stainless steel look seems like it would be harder to replicate, because of the coating.