While I'm writting quickly, I can read and type at 9 characters per second.
That is, when writting, I click 9 keys a second, on average.
That's 111.11111[...] milliseconds per key.
When I'm playing, I know I can do more than 15 keys a second.
That's 66.6[...] milliseconds per key, or less.
Setting to around 0.05 of time between key should be enough.
Now, you need to take into account on how long you hold the key.
Using this page:
https://dvcs.w3.org/hg/d4e/raw-file/tip/key-event-test.html
I've inspected the input and added the following code to the console:
Code:
$0.addEventListener('keydown', function(){console.log(new Date())})
$0.addEventListener('keyup', function(){console.log(new Date())})
This tells me when the events occurred, on Google Chrome.
With that, I've determined that I take 25~50ms with the key held down, per click (this is a visual observation!).
Setting around 0.04 won't be too bad for me.
If you use macros, go for 0.
More dps for you!