Reviving and old thread. I'm on my (cough) 4th htc one and I just bought a dd flip. My father in law has one too. Both cases are totally different. Mine is smoother and thinner. His is thicker and more leather like with way more creasing and embossed deeper. It's also slightly thicker. They must have revised them. 6 months difference in purchase date.
N1 to SGS2 to SGN to HOX T3 to G1 Dev ed. grey Lumia 920 to yellow 920 back to N1 then a Sony Xperia Z via a Mozart and now a black and a silver M7 and now a Nexus 4 and a HD2 running WP7.8 and then a Note 3 back to a silver 64gb HTC One M7.