Pull up friends list
One extra-simple function found on the GamePad's touch screen is the ability to quickly pull up your friends list. The list still displays on the TV screen, but pressing the button on the touch screen is faster than opening up the start menu and accessing the friends list from there.
From your friends list, you can see who's online and what they're playing, and quickly join other players' games or invite them to your own. Standard stuff, of course, but it's the little things that count when you're looking at the differences between platforms.