The Z line is Zegna's sportier, fashion forward child. I see the stuff heavily marketed at Harry's, but I don't see the edgier pieces of the collection. I guess that wouldn't fly with their Bay St. clientele.
This particular collection was intresting, albeit very black. Most men's magazines will tell you not to wear an overcoat past the knee, but this collection (as well as many others) violate that rule. As for me, being a shorter dude, I would never wear anything past my knees.