Did you try the config: pressedDelay: 0? The default is 100 milliseconds I think....
Is your DOM heavy, causing your app to be slow (are you using a heavy tabpanel for example)? Once your app is loaded, in your console copy and paste this (right click, inspect element, paste):
How many items does it say? about 400, or is it closer to 1000? I used an optimized tab panel, removing the DOM items after each tab click and I get an average number of 250.
Also have a look here: