I'm interested to get some feedback from admins / engineers on their migration path experiences. I'm running 2007 exchange on private cloud at present. I am considering 2013 exchange in azure but have since found out there are issues with load balancing so it looks like on prem in my private cloud is the only way to go. Office 365 is another option but throws up major issues with performance for terminal services and Citrix. I'm aware of companies that have moved from office 365 back to on prem as the experience was bad. The hybrid model also throws up issues with sharing calendar, shared mailboxes and O365 users sending via cloud smtp with local mailboxes using the on prem smtp.
I'm only referring to larger networks 500 user plus. Thanks