Item 38: Understand the Pros and Cons of Dynamic(Effective C#)

There are also performance costs with using dynamic and with building expressions at runtime. Just like any dynamic type system, your program has more work to do at runtime because the compiler did not perform any of its usual type checking. The compiler must generate instructions to perform all those checks at runtime. I don’t want to overstate this, because the C# compiler does produce efficient code for doing the runtime checking. In most cases, using dynamic will be faster than writing your own code to use reflection and produce your own version of late binding. However, the amount of runtime work is nonzero; the time it takes is also nonzero. If you can solve a problem using static typing, it will undoubtedly be more efficient than using dynamic types.