AET advantages over EEWB

Hi,

iam new sap crm,

I have read through many threads in SCN,but iam unable to make out the exact advantage of AET over EEWB,
Except that AET is integrated with WEBUI,
Can anbody guide me more advantages of AET over EEWB and how it is inter related to different layers in sap crm.

Thanks
Anil