Google for Work vs. Microsoft Office 365

Roger Kolman ASKED

We are seriously considering cutting the strings in our city and moving everything possible to the cloud rather than owning and maintaining our own servers. As part of that process we are also discussing the migration away from our Exchange server to one of the two "giants" in the cloud based email/productivity suite market. Does anyone have experience, good or bad, in migrating to either Google for Work or Microsoft Office 365? Any, in retrospect thoughts about your decision? Realizing that change can be threatening to many people, any advice on helping users that have become used to the look and feel of a certain product to accept and adapt to a different product?