Why is the use of reflection in .NET recommended?

Question

Is it definitely a good practice to use it?

What are some possible situations in a project that need reflection?

Answer 1

Coming from C++ and having needed some simple class hierarchies, I can say that the is keyword is invaluable!

class MenuItem : Item { }

foreach(Item items in parent.ChildItems) {
    if (item is MenuItem) { /* handle differently */ }
}

P.S. Isn't reflection slightly expensive, btw?