Pros
I loved working as an SI Leader because you are put into courses you have previously taken that you excelled in. The upperclassman who have had SI Leader experience help you through the process of... what it means to be an SI Leader and provide all the information and training needed.
Cons
Sometimes the courses you get put into are not your top courses you have provided in your application.
Pros
Wonderful co-workers; everyone is collaborative
Cons
Old school way of getting things done (because people have been there forever and old habits die hard)