Undercharging the iPad

John Brownlee, referencing an email from Dr. Raymond Soneira which stated that the new iPad may continue to draw current (charge) for up to an hour after the display says "100%":

So if you’re charging your new iPad for eight hours every night, time to start charging it to 9 if you really want a full charge for the day ahead.

There are so many things wrong with this statement. How uncharged was the iPad when you plugged it in? "Up to" an hour does not mean a solid hour every time. Do you honestly need to charge every night? I charge my iPad and iPhone only every other day.