We've got some Office 365 users that have been on for years, before it was called Office365 in fact. Back then, the Enterprise plans had larger mailboxes and more features. So all the users are on Exchange Online P1 plans. Back then there was also no way to switch between Enterprise plans and regular business plans without exporting the mailbox, re-configuring things and re-importing them.
Now it appears you can indeed switch between Enterprise and Business plans. So it seems we can move users from that Exchange only plan to the Business Essentials plan for $1 more per user and get Lync, Onedrive for Business etc. And if they want to start subscribing to full Office, that is considerably cheaper than the Enterprise plan.
Seems like a good deal and a no brainer, but am I missing something? What functionality are we losing by switching...