I swear by my clit mouse. And it loves me back
The killer feature that makes it superior than either regular mice or trackpads (for general use, websurfing, word processing, coding, and certain games) is that you don't need to move your fingers from their standard typing position on the homerow. Also, it wins at certain games because you can move indefinitely far in one direction without "scrubbing" (lifting up the mouse and putting it back on the other side of the mousepad), which is slow and imprecise. Obviously you still need a real mouse to play FPS games and the like.
My fingers never get tired during normal use, even for marathon coding/browsing sessions. Long gaming sessions can be a pain though since you typically have to press harder to move faster. Contrary to popular belief, normal mouse movement requires almost no pressure at all. The only real pain is when it gets moist from sweat or something, and loses its friction.
Oh, and I always call it a "pointing stick" in polite conversation, even though I'm thinking "clit mouse".