Pretty much same as the 1902 caseback wise. It manages to achieve a different look to the other 19 series watches, but I prefer the gradient dials of the older watches. Makes them more distinct and interesting.
What I find odd - the 1901 and 1902 were available as production series and were not sold out until Ming decided not to make more. Make something limited and they fly within minutes. I guess more recognition means people now willing to pay the higher end (fully justified, they are significantly better watches).