... and I like it quite a lot. The buttons are easy to press (left click with thumb - finally!) and the Trackballworks software allows to remap them to almost anything, although it misses a setting to increase the scrollevents/rotation ratio. Scrolling (rotating the ball horizontally) can easily be done using only one finger. I love the sound that it produces, it's like fine tuning a delicate mechanical instrument. Also, my concerns, it would not allow fast enough mouse movement for lack of dpi, were unfounded.
I tried two other devices before the Slimblade, namely the Wacom Bomboo Pen and Touch and the Logitech Wireless Touchpad. While I deeply disliked the Wacom tablet, because it fails so very badly in almost every way possible, i found the Logitech Touchpad te be quite pleasant. It looks chubby in pictures, but actually it's pretty nice. Unfortunately its buttons were hard to press (*YES! I measured!!1) and felt kind of springy, and Logitech's drivers aren't as configurable as Synaptics'(**). Lastly, barely noticeable: input lag. Not a deal-breaker for me (***), but still a slight turn-off in the first few minutes.
So I'm going to stick with the Slimblade, which probably also is more ergonomical, since my wrist moves less using it.
* It took a whole brown cherry spring + slight force to actuate, while my Logitech G9's and the Slimblade's buttons actuated just before the spring was completely compressed.
** Most laptop touchpads are made by them.
*** not a big shooter fan and probably would've used my mouse for that anyway