I like to have my key repeat set high, because I still browse my code line, by line; yes, I know there are better ways to browse.
On the Mac, if you go through the “System Preferences”, there is only so much you can do. Luckily, you can get the right settings if you use the terminal.
First, make sure that you have disabled “Slow keys” in “System Preferences > Accessibility > Keyboard > Slow keys”.
Then go into your Terminal of choice and type:
defaults write -g KeyRepeat -int 1
defaults write -g InitialKeyRepeat -int 12
The normal minimum of KeyRepeat is 2. Setting it to 1 will have a key repeat
delay of 15ms.
For the InitialKeyRepeat, the minimum is 10; 15 if you use system settings. I
prefer to set it to 12.
If you want to restore the defaults, just go through the system settings and set it to a value you prefer.