It really is a unique shape while being VERY ergonomic. I've used one, and it hands down is the best mouse available.
Just yesterday I received my Razer's DeathAdder mouse, this mouse is awesome in many ways. First thing, it really looks incredible! Second, just put your hand on it, the surface feels incredibly soft to the touch it has this ultra soft type of micro-velvety feeling surface, unbelievably pleasant to the touch. Scrolling wheel is awesome too, large enough and silent and with a smooth movement. Size of the mouse is great even for long hands like mine. Tracking is wonderful. Teflon feet move absolutely seemlessly and silently on anything. The mouse is very quite, and the clicks on the buttons are just right. Icing on the cake, the very slowly pulsating blue light on its loins, such a cool touch. Really well done in all respects!
PS. Amazon review added.