Moving from POP3 to Exchange

Businesses are find great value in either using LotusNotes/Domino or Outlook/Exchange as their communications platforms. Maybe Colleges/Universities use best-of-breed products instead of these groupware packages as they fear the proprietary environment.

Have others moved from a POP3 and independent calendar management to a groupware product? Have support and support costs changed? Was the transition difficult? Were users and management pleased? Would you do it again?