We switched 3 months ago from our local exchange mail to Google Apps Premier solution, and I have to admit, this was a hell of a smooth transaction. I remember our switch almost 10 years ago from POP email to MS Exchange and it took us almost a week to get the system working. With thatWise support we were transferred over in one weekend. So on Monday we were using our new e-mail system including full access to calendars and contacts from iPhones and Blackberries. Now, 3 months later, I can say without any doubt it was the smartest business decision we made this year.