[QUOTE=FrontFive;20463677 The arguments about the additional stiffness of a double diamond frame makes sense when talking about a bicycle built for speed and handling, but when you just want to get from A to B safely and in comfort then the value of those benefits of the double diamond frame reduce drastically.[/QUOTE]That reduction is relative. It's not additional stiffness, if you design a frame for it's primary function, connecting two wheels and a bracket to get forward motion from human energy, a step through is not a good design. I like them, I like the way they look, I like the riding posture of an oma both for ladies and for myself, I like it that there are bikes for people who can't swing their leg over, for people who want to cycle wearing a dress or skirt and who want to carry one or two childeren on the rear rack, but it's a compromised design because of it's reduced stiffness.
It's been quite a good compromise since 1904 and it has gotten better with aluminium and different step through designs, but it still comes with drawbacks. How big the drawback is depends on the size of the frame, the weight and strength of the rider and the speed he or she wants to travel at. For me as a tall man it becomes very real when A and B are more than 2 km's apart and I want to get there at 20 km/h safely and in comfort. It's the difference between sweat and no sweat. I'll happily ride a step through, but not as my own daily bike. For me it's not the difference between a girl's bike and a men's bike, it's the difference between a general purpose bike and a bike that fits my needs.