I am working on a application design and investigating on passing data between WCF services and the ASP.NET web application. Options I am looking at are to either use "Datasets" or Entity Framework.

I have bunch of questions,

1. If I use Entity Framework to pass data, would it add more overhead to the WCF communication,
2. Is Datasets considered as "light weight" considering the communication overhead,
3. If i use Entity Framework, how can I maintain object models if I use stored procedures to return complex data?

Overall I need to figure out pros and cons of using these technologies.