Always use ASP.Net State Server during development
http://msdn.microsoft.com/en-us/library/ms972429.aspx
Using “ASP.Net State Server” during development forces developers to use serializable-attribute on all objects stored in Session.
Reasons:
- No extra effort required by the developer.
- Changing to ASP.Net State Service or SQL session storage on a solution not developed for it requires a full and extensive test of the whole solution.
- If the server needs to be set up with round-robin or load balancing the solution already support it.
- When solution is deployed to production the default inproc (non-ASP.Net State-server) session storage can still be used.