Integrating CRMOD with Oracle EBS using AIA / PIPs

Hello,

  We are toying with the idea of deploying CRM On Demand solution for one of our divisions which is already using Oracle EBS for Order Management. The idea is that CRM On Demand solution will be leveraged for much of the sales processes replacing the functionality offered by Oracle's Contact Center. What is the level of effort required for integrating the data using the prebuilt PIPs offered by Oracle using the AIA architecture?. One of our divisions is already using CRM On Demand integrating data using web services.

 Any comparison with respect to the level of effort required using PIPs ( especially when reflecting on going changes to the application i.,e., adding new fields to be integrated ) v/s Web services would help.