Macbook trackpads are so nice and large, and with gesture support they're so useful.
Upon saying that. If you have a good mouse with good DPI, you shouldn't be constantly relocating your mouse. When I used to use a nice mouse before it went walkabout I was able to move from one end of my screen to the other without ever lifting the mouse. That's how a mouse should be calibrated.
I use dual screen and I only need to move the mouse about an inch or slightly more to move completely over both screens.
Only slightly related: I also have a "shuttle" on the left-hand side, it is wonderful for audio editing. I highly recommend such a tool for podcasters and other sound-making people. It's nice to pan and zoom effortlessly.
Trackballs on the other hand... I still have my Logitech wired TrackMan with the ball under my thumb.
I use a trackball, a highly underrated input device.