Perm url with updates: http://xahlee.org/emacs/keyboards_Apple.html
Xah Lee, 2006-06, 2010-06-12
Keyboards (and mouses) from Apple ever since the iMac in 1998 are in general the most ergonomically painful.
Hard-to-reach Right Alt Key
The Apple keyboard from 2006.
Note the ridiculous distance of the right side's modifier keys. It is not possible, to use the right thumb to press the alt key while the index finger remains on the J. It makes these keys essentially decorative in nature. (Apple did this to make the keys flush at the lower right corner; sacrificing function for esthetics.)
Another utter stupidity is that the function keys are all squished together into one beatific contiguous row. Traditionally, they are separated into 4 blocks. The one-contiguous-row design makes it difficult to sense the right key position by touch.
Apple's full keyboard, as of 2008. The right side of modifiers are still too far to the right.
Apple's keyboard as of 2008. Image Source In this model, the left and right “command” keys are symmetrically placed with respect to F and J keys.
Apple's keyboards are usually the worst keyboards with respect to ergonomics.
Position of LED for Caps Lock
Also note the LED indicator for the Caps Lock key. It is right on the key. You would think that is good design, but actually not. Because, when you are typing, you can't see the light there. It's actually better, to have the light indicator elsewhere on the keyboard that's easier to see. For most generic PC keyboards, it's on the upper right side on top of the numerical pads. On some Microsoft ergonomic keyboards, they actually moved it to the middle of the keyboard. (See: Microsoft Ergonomic 4000)
Placement Of Multimedia Keys
Also note that Apple combined multimedia keys (such as volume control) into the functional keys. This means, when you want to use functional keys, you have to hold down the “fn” modifier first. This is a pain in the ass. Apple do this because they believe in some kinda visual elegance, and consider separate multimedia keys too complex or esthetically unwieldy. Apple computer, software and hardware, are usually of high quality in terms of design with respect to function. However, in some department, such as keyboarding and mouse, they sacrifise function for esthetics. This is idiotic.
Also, multimedia keys, such as volume control, next/previous song, mute, usually have different shaped buttons on most keyboards.
Microsoft's ergonomic keyboard. Special keys are shaped in a special ways, increasing tactile feedback and visual recognization.
That is a good design quality. Because, different shapes for special keys increases tactile recognization as well as visual recognization.
Some keyboards, even use a rotary knob for volume control, which is even better, because rotary knob fits well with the control requirements of volume change. When the volume control is a button, you need to press it multiple times. With a rotary knob, you can instaneously change volume to desired level, or reverse direction.
Uniform Rectangular Array = Unnatural
Human perception is not optimized to deal with uniform geometric arrays. A array of neat rectangles may be esthetically pleasing, but it is not a form that occurs much in nature, and makes it more difficult to recognize or hit the right key.
By making the keys of uniform shape of rectangular array, you take away the ability to distinguish keys by tactile sensation. User must look at the keys or grope by positional sensation. Groping by position is made further difficult because the keys are not grouped in small clusters, by the lack of gaps between key function groups.
Function keys are important for programers as well advanced keyboard users. They are very useful as single-press shortcuts that are customizable.
Difference with PC Keyboard
Note that Apple's keyboard and PC keyboard have minor differences in their set of keys. Namely: Cmd, Opt/Alt, Windows key, the Delete and Backspace key, Enter and Return keys, the PrtScr, ScrLk, Break vs F13, F14, F15 keys.
Some of these differences are mere difference in labeling of the key, but not all. For detailed comparison, see: Difference Between Apple and PC keyboards.