Man is a creature of habit ...

The product appearance is ok, the feel also, several providers have apparently at this manufacturers are working, whether Perixx or CSL or whatever hot. The mice are all almost identical.
The mouse as such also works on most surfaces, not on glass.
In fact, the ergonomic effect sets as described, but unfortunately compensated an unpleasant strain of the outer right carpal bone, called pisiform, the positive effect. In a flat or only slightly sloping mouse Aufstützbelastung is distributed over the entire wrist, now only on the right side. This is not really relaxing, because the reaction force in the wrist almost doubled it.
Another disadvantage that can be overcome only by long habit, is the new motor skills required. If you could previously access with a wiping motion of the keyboard to the mouse, you now have to raise the right hand deliberately to get over the "hump mouse". I for one often suggest to the new vertical mouse that then every rumbles under the table. For a 10-finger-writer that's kind of annoying to write and do not keep in mind that the Mausttasten "rear" are not more above but rather. Let's see how long I think that before I return my Logitech Performance MX back hole, the contact effect often described shows now so extensively unfortunately after two years, that even to do with brutal thumping handshakes on the left mouse button to clean the contact surfaces nothing is. Nevertheless, Logitech has the ergonomically more coherent concept for me.