My keyboard repeat rate is set at 80 characters per second. I do this to be able to navigate in the code faster.
When the rendering performance is bad (such as on the Retina MBP) the keyboard repeat rate in Sublime is capped at the rendering rate (does not happen on Windows version). This does not happen in Xcode for example so I suspect that it's not an inherit limitation of the event loop in OSX.
Even if the rendering performance was optimized, it would still be capped at the vertical refresh rate (60 Hz in my case). If all outstanding events were processed before rendering this problem would probably go away, as well as the problem in https://forum.sublimetext.com/t/typing-very-slow-delayed-even-on-small-files/2996/1