Microsoft
I take that back, I must have fat fingered the data input my first try.
Our same user messaging profile in 2010 takes 20% CPU utilization on our 8 core SPECInt2006 rated CPUs of 251, and in Exchange 2013 the exact same configuration (user messaging profile, DAG configuration, etc) takes 111% CPU utilization.
Thats a 500%+ increase in CPU requirements and we had hoped there was a mistake in the calculator math because while we understand there is more work going on the mailbox role in 2013 (hub transport is integrated, multiple STORE worker processes now, database page compression, etc...) that seems excessive.
