Ugh, people with nice, sexy mice make me hate my desk setup even more :-/
The height (not adjustable) is just slightly too high to be comfortable for my arms, meaning that most of the time, my mouse arm is angling up to the desk, cutting sharply at the wrist. Can't push it back further on the desk because of an annoying "shelf" thing that forces my second monitor very close to the front of the desk, so the positioning stays.
It mostly means I can't comfortably use anything but the absolute flattest of mice, as otherwise, the angle makes my wrist start to go nuts after 30-45 minutes. Bought an MX518, loved everything about it except the pain it caused (and it's not exactly the tallest mouse on earth), and had to swap it out for a much less sexy, albeit functional, MS mouse :(