Exchange 2013 IOPS Requirements for ActiveSync and anti-virus

I am currently planning to replace my Exchange 2003 server with Exchange 2013. I have used the Exchange Server 2013 Role Requirements Calculator but I'm stuck on how much additional IOPS to add for ActiveSync and my anti-virus solution (Symantec Mail Security for Microsoft Exchange). The only info I've found for ActiveSync in regards to additional IOPS is to add .5 but nothing for SMSMSE. Symantec's web site has nothing on this (the question has been asked but not answered). I've also seen the ActiveSync question asked but not answered.

Any advice or guidance would be appreciated.

Thank you.