Communication Method Between C4C and MDG

Hi Experts,

We are implementing MDG C and we have C4C in the landscape which is leading system for Customer Creation.

C4C will send the message to MDG via PI and then MDG will then trigger the CR automatically. MDG will then replicate the Customer master , once approved, with Customer no to C4C. This is quick overview of the process.

My question here is which is best method of communication between C4C and MDG. Is it Web service or IDoc?

I have gone though the blog available by Amitava Mitra where he mentioned about Web Service message between PI and MDG.

But still I would like to know expert's comment on why Web Service is preferred against Standard Idoc in this integration.

Thanks

Rahul Kulkarni