Actually I love picking Nunu into CC-heavy teams and building plenty of tank on him. Using your W on your AD provides massive damage output for them and you can use your E to slow anyone that tries to dive your carry. Building plenty of tank means that you'll survive all the CC they throw at you, and since you're Nunu they almost HAVE to blow CC on you in teamfights. It gives your carry a break.

You really should! You of all people would agree that picking Nunu & Willump into a solo lane means your other teammates have to bring the damage, to just name one. I also foresee Nunu & Willump being a bad pick against CC-heavy teams, since his biggest source of damage is also his most unreliable one.

While he might not have the DPS or Burst you see from the champions you mentioned, I did mention in the guide that Nunu as a full-AP carry is lacking in terms of usefulness.

The entire guide revolves around Top lane Nunu, and the reason he excels top lane is his vicious laning phase (A lot like Riven, Renekton, and other hardcore laners). The Top-lane build involves a good bit of tank and a lot of utility. You get incredibly tanky for the items you actually have and late-game can often kill their carries quickly OR easily peel for your carry. Your comment did make me realize something though, I will add a "What kind of teamcomp Nunu should be in" section.

Thanks for the input :)

Overpraised, definitely. Nunu & Willump is certainly not as good as you make him out to be. If not, you'd always be seeing him in mid and top, but why is this not the case? The answer: His biggest con, which you left out, is that he is very weak late game. He doesn't scale well when very farmed, which is why he is most commonly seen as a support and jungler. He has neither the burst of LeBlanc, Ahri, Brand, Veigar etc, nor does he have the dps of Ryze, Cassiopeia or Karthus. He works well as a counterpick to make his opposing laner underfarmed, but as a main pick he isn't that strong.

Veeeeeeery well done ser

+1 for you! :D
-Meiyjhe