What are the Advantages of DLL over User Control?

Question

I have a asp.net user control, with me. Even though it is a server control, all the functionalities are implemented in client side (in an external js file) for lightweight & for efficiency. I have used Jquery widget pattern.   

 

Now, I feel that, converting the user control to dll will help me to maintain the code easily and also i can use the power of c# as well. 

 

I am not so confident with this idea. I need help.

 

Here is my question.

 

What the other Advantages of converting User Controls to DLL ?

Does it really helpful?