[Strilanc]

Because blocking on tasks is a deadlock waiting to happen [0], and creates UI hiccups when the task takes longer than 16ms to complete.

In other words, the conditions you must satisfy for using Task.Wait or Task.Result are very complicated. They depend on and create global constraints of the entire program, and so you should avoid using them whenever possible.

0: http://blog.stephencleary.com/2012/07/dont-block-on-async-co...

[jasallen]

That deals particularly with mixing and matching awaits and Results in complex manner. I wouldn't call "don't do that" "very complicated".