I finally sold my shiny “like new” Apple aluminium full-size keyboard (2008 model). It is a magnificent piece of hardware that had me drooling for days during the past winter before I took the leap and bought it. It is slim, looks good (that’s subjective), is built tough, and can act as a limited USB hub.
There is one critical thing where it went wrong: this particular keyboard causes RSI (at least in my case; your mileage may vary).

I came to this conclusion when I had symptoms of pain “in my fingers”. I wouldn’t say the joints, as it feels as if the bones themselves were painful. A disgusting feeling that even exercising (or cracking) your fingers can’t get rid of. The suffering builds up and can prevent you from typing for a day or two, and leave you confused as to what the heck is happening to you. For the record, I’m 21 years old and used the keyboard all the time since I was 7; I had never felt this before, and it was quite sudden.
In good empirical fashion, I decided to switch back to my cheap plastic Dell keyboard for a while, and back and forth with the Apple aluminium keyboard, leaving a few days/weeks (I can’t remember exactly) between each switch.
The end verdict is that the Apple keyboard is indeed causing RSI. This has been corroborated by the fact that I have been using extensively an IBM Thinkpad laptop (with the “legendary” thinkpad keyboard) for the past six months or so, and I never experienced any pain again.
So, I felt sad to sell my really nice, sturdy, quiet, sexy Apple keyboard because the damn thing is dangerous. You sure won’t see that in Apple’s marketing.
Now, I’ve spent a good deal of time reflecting upon the causes of this phenomenon. Why is it exactly that this particular keyboard induced serious pain in my fingers? Based on some research I did on the net, discussions with relatives and some more thinking, I came to suspect the hard aluminium surface, combined with the fact that the keys are extremely flat.
This means that when you press a key, the key does not have enough “depth” to absorb the kinetic energy of your finger. In other words, each time you press a key, your finger’s bones slam onto aluminium, with almost no dampening of the impact; stressing your bone/joints with insufficient keystroke impact cushioning would be the most probable cause of RSI that I can think of, in this case (the keyboard position, height, and other factors were controlled in this “experiment”). Combine this with a heavy typer like me (80 words per minute), and boom, you got your disaster.
Even the cheap 10$ plastic keyboards are better than the 50$ Apple keyboard in this regard. But you will only find out about RSI after using it intensively for a month or so. Fail.
I can only hope that Apple (and other companies) do not repeat mistakes such as this again. When I did research on the matter months ago, there did not seem to be any public outcry on The Internets about this keyboard causing RSI. Perhaps I am the only one who experienced such a problem, I don’t know. The one thing I know is that I cannot use this keyboard.
I would be interested in any recommendations for a good, lightweight (and small, does not need a numpad) keyboard for carrying in my laptop bag. It has to be no larger than a regular laptop, USB, not expensive (ha ha ha) and come as close as possible to the comfort of the IBM thinkpad keyboard. I know that you can buy the thinkpad keyboard as an external keyboard, but it’s a tad expensive to my tastes. Either that, or I need to find a nice seat cushion to elevate myself to the level of my laptop during classes (the seats are not adjustable, and you are bound to the table, which is too high).
2017 update: you might also want to read about my 2013 DIY sound suppressor for the Unicomp / model M keyboard. Also, learn to type in Dvorak.