This hidden setting will speed up Haptic Touch, the fantastic feature that lets you preview links and bring up option menus on your iPhone.
If you use Haptic Touch all the time like I do, changing this setting will make your iPhone feel supercharged. It brings up handy shortcuts — hidden actions, content previews and contextual menus in a flash, saving you precious time as you tap around your screen.
Alternatively, if you find Haptic Touch annoying and trigger it accidentally all the time, you can slow down the time needed to activate the gesture. That way, a tap won’t be mistaken for a tap-and-hold.