<p>Which of these pieces of code is faster?</p>

<pre><code>if (obj is ClassA) {}

if (obj.GetType() == typeof(ClassA)) {}
</code></pre>

<p>Edit:
I'm aware that they don't do the same thing.</p>

This should answer that question, and then some.
The second line,
```
if (obj.GetType() == typeof(ClassA)) {}
```
, is faster, for those that don't want to read the article.
(Be aware that they don't do the same thing)