Using session object or custom state management for collection property in a server contro

[whoisnidhee]

I have a server control that uses a collection property - ArrayList.
How do I store the Viewstate of the control? Which option is better in
this case, custom state management (by implementing IStatManager
interface) or by using a Session object?
Using a Session object is definitely easy but how does it measure
against custom state management of the server controls?