Compare MVC 5 ASP.NET role provider and custom role provider?

Hi, I am building a new MVC 5 application, still not sure should I choose the MVC build-in ASP.NET role and membership provider or should I build custom role provide, the concern for me to use MVC build-in ASP.NET role and membership provider is that the database for user management is slightly different to the ASP.NET role provider SQL tables, I am just wondering if it is possible to modify those ASP.NET role tables, such as add new fields in the table like 'AspNetUsers' and properly add extra table for the user management on top exiting ASP.NET role and membership tables?
Also if I build the custom role and membership provider, is there any benefits for that?
Please advise!