A month into using it, I would like to say that the Delux has actually been great and comfortable to use. Not sure what I've done, but I seem to have harnessed the axes somehow, while still being able to use other mice just fine. And once you have the DPI where you want it, you don't really ever have to change it (I don't game, so I don't personally have the need to, but I also can't foresee too many people gaming with vertical mice).
One issue I have is that without a driver, the buttons can't easily be re-mapped, so I've just re-mapped the Evoluent VM4R that I use at home to use the same buttons (lower thumb button to back, upper thumb button to forward) for an easier transition when I get home.
Also, the Delux's palm grip is rubbery. Not a pro or a con, just something to point out.
Still personally like this better than the re-branded Wowpen Joy I had, which while mostly comfortable, had a chattery scroll wheel and thumb buttons that my small hands had trouble reaching.
