The one thing I find a bit uncomfortable on my cab is buttons...as my arms are angled down towards the CP, my hand is therefore resting on the CP, angled upwards. With my arm angled down and hand angled up it gives me a painful wrist after a while.
I find myself standing with my legs quite far apart, effectively making me shorter! Sitting on a stool improves it no end also...
Advice from a long time Asteroids/Gravitar/Star Castle/etc.... player.
Take a half step back, and bend at the waist to straighten your arms out, so that you are not bending your wrists.
I used to play for hours this way.
It's the only comfortable position I've found for using buttons.
If you bend your wrists, you will develop carpal tunnel syndrome, from sawing at the carpal tunnels with the tendons in your wrist.
This same wrist position lets me play FPS games for hours without discomfort as well.
I have 12" of desk between the edge of the desk and the front of the keyboard on my main comp, for exactly this reason.
The straighter you keep your wrists while typing/button pushing, the happier they are going to be with you.