Timing belt for cx7

[Isac]

I have a 2009 model Mazda CX7.When I did the the last service, mechanic told me that timing belt is started degrading. He is saying this is the right time for timing belt replacement. In the coming week I will give my car for the next service. What will be the better option among neoprene and EPDM timing belts? If it is possible share its advantages too.