Chalk me up for anecdotally noticing a huge improvement when switching to the touchpad.

It's worth noting that the Apple trackpad is not only way bigger than a laptop's touchpad, it's also angled so you're not resting your hand on its edge. Also, if you've never used an Apple touchpad on a recent Macbook/Pro (the ones that are glass instead of plastic), you'll probably be surprised at how good the accuracy/tracking. They're much better quality than the Synaptics touchpads that are common in PCs.

I find myself supporing my fingers over my Magic Trackpad, which is tiring. At the very least I have to raise all my fingers except the ones I want to use in a gesture.

My other preferred device is a thumb-ball trackball. I have a logitech trackman, and the discontinued one from Microsoft. I find those much more comfortable, if a bit problematic for high precision. I just wish I could get a bluetooth one.

I have all of the input devices mentioned in this thread, and cannot find anything to compare to the old Kensington "Expert Mouse" track balls, with the heavy ball the size of a billiards ball, a scroll wheel around it, and 4 buttons.

The ball's diameter allows pinpoint accuracy when needed, the weight allows a flick with momentum to carry the cursor across two 30" screens, the scroll wheel is under your ring finger for simultaneous use.

That said, the recent magic trackpad is growing on me.