While a lot of opinions vary because using different peripherals induces different types of stress on the body.  Trackpads are mostly popular because of the multi-touch gesture controls and it lets people tend to be more lazy and not move more than their hands but lack of full arm motion can just focus the strain as well as potentially reduce circulation.

It also depends on what you’re doing as some applications tend to induce a lot of repetitive actions.  While trackpads tend to be less precise than a mouse and not all multi-touch gestures are executed correctly all the time.

In terms of business use and things that Macs are generally used for like video editing and graphical applications are things that promote repetitive action and for long periods of time that in turn increases chances of RSI.

For general consumers the Magic Trackpad is much more beneficial that don’t have to worry as much with doing the same thing for long periods of time.

Though the Magic Trackpad is worlds better than the good old days of when all Macs used one button mouses and the debacle of the round iMac mouse.  Boy did I hate those… While trackpads in general use to be terrible back then with single touch and no gesture controls.  So things have improved… Just don’t assume something is automatically beneficial until you’ve tried it and confirmed it works better for you.

After all we’re all different and there’s no such thing as just one single better way of doing work…

While the touch gestures are nice for certain applications, it doesn’t automatically make anyone more productive, but people tend to have more fun with them and so it gives the perception of providing more productivity and for employee satisfaction that alone may justify it.

Regular PC’s still have a way to go with Trackpads, at least afford-ably as Wacam pads are arguably even better, but Synaptic drivers can provide most with similar level of gesture control usability and it’s just strange not more systems use their drivers.

Depending on the industry, a macs extra cost can be returned many times over in productivity gains. When considering the trackpad, even lowered insurance costs from repetitive motion injuries can be factored.