Hapi was developed and is still being used by Walmart. Being backed by such a major company means that it will not lose support any time soon and most importantly it's being developed by professionals and that you will always get support for it.

Pro
Consistency across applications

Hapi's philosophy is that configuration is more important than code. This is especially useful for very large teams because it helps developers maintain consistency and reusability throughout their code.

Cons

Con
Requires too much boilerplate

Hapi seems to be made with large applications in mind. The sheer amount of boilerplate code it requires is simply not practical for a small web app. This also means that there are few examples of Hapi applications around for beginners to learn from.