In response to njnookman:
I doubt it's a user intelligence and more a fact of the type of touchscreen. FWIK, the touchscreen is monitoring the difference in capacitance on the screen from no touch to touch. Different people's skin will conduct differently, and the oil left behind will affect things as well. That may well explain your experience - after using it a while, you've left more of your own oils on the screen and the system is better at determining the difference between touch and no-touch. Hand it to someone else, and the device has to fight with the difference in oils in addition to the difference in skin capacitance. But, I'm mostly guessing here...
I've noticed the "N" button and "touchscreen wakeup" from tapping the touchscreen directly work differently based on what activity you're currently doing.
For instance: while reading a book, tapping the touchscreen does NOT wake it up. I'm glad for this because lightly brushing your had across the screen while reading would otherwise easily wake up the screen - in addition, the screen stays off so the touchscreen can be used for the new useless swipe navigation. Anywhere else in the menu system except reading, touching the touchscreen will wake it up.
While reading a book, placing your finger on "N" for about a second will wake the screen without sending you to the main home page. Pressing N for a few seconds after the touchscreen is awake will send you to the main screen, closing the book if one is open. I believe the delay is a good UI design, because it stops it from activating things due to a random light tap of a rogue finger or hand while reading.
I guess "pressing N" is wrong - as others mentioned, no pressure is required and may be counter-productive. Simply lay your finger on the touchscreen or N to trigger the response.
As someone else noticed, keeping the touchscreen (and N) clean of oil will likely help improve it's responsiveness.
Understanding those above "features" made my experience with the touchscreen much better. The only problem I continued to have was in the scrolling lists - it just never went where I wanted.