I currently own every "Next Gen" system or now current gen. It may seem unnecessary and in reality it is almost unnecessary but I do love me some video games. With all that in mind I can honestly say the Wii U Gamepad is one of my least liked controllers of maybe all time. Now that may seem harsh and unwarranted but simply put, it is pointless. Most Wii U owners will claim you must use it in order to really love it like they do but in my case it had the opposite effect. After purchasing the console a month from launch, I realized how useless the gamepad really was. I hoped for some incredible multitasking abilities.
Before you go off claiming I am just another hater/ fanboy give me a chance to explain. First lets break the myth that the Wii U is a great deal because you get a console and a tablet. The gamepad is always tethered to the console so it is useless ten feet away from the console. Everything that is happening on your big screen is also happening on the gamepad. It would have been pretty sweet if it actually did act like a tablet and allowed you to play some Netflix while playing a game but alas it is a missed opportunity. You are better off purchasing a cheap tablet that is capable of doing a lot more than the gamepad.
Just wait for the next Zelda they say, having your inventory or map on a second screen is revolutionary. How about actually using good game design to create a less abrasive hub. Nintendo believes that there should be new ways of playing old games. Instead Nintendo should use their creativity to change the formula of old games. Just look at games like The Last of Us and Dead Space in which the inventories are cleverly integrated into the experience, adding to the tension of both games. The inventory and hub became integral parts of the game design. Looking away from the television screen really takes you away from the experience and the whole point is to make a really immersive experience.
None of the games currently out use the gamepad in any meaningful way. The best use of it comes from ZombiU in which going into your backpack means having to look at the gamepad. Like I mentioned before, looking away from the television screen takes you out of the experience. The Legend of Zelda: Wind Waker HD and Darksiders 2 both use the gamepad for inventory but does it make the experience that much better? Some argue that it does make a huge difference but does that justify having the gamepad exist? I think not. At the end of the Wii U's life cycle there may only be about a handful of games that take real advantage of the gamepad and that is just not enough.
The last reason I dislike the gamepad is the layout. Now this is problem that is not exclusive to the gamepad. It is also a problem with the Wii U Pro Controller. Having the analogue sticks placed above the face buttons is a huge annoyance. Granted this is more of a personal annoyance, but it is just another thing that Nintendo must do to be "different".
Of course these are just my opinions so feel free to disagree.