Comment 5 for bug 1571513

I just noticed also with sounds off, you can hear the impact of your finger tapping the screen before the vibration occurs. So our haptic feedback is slower than the speed of sound. :)

This fix should help a bit: https://code.launchpad.net/~vanvugt/unity8/fix-1497105/+merge/314212
But I would still recommend turning off touch vibrations.