I should have mentioned Google - but this wasn't really a comprehensive review - just my first thoughts.
I store my contacts/calendar info in Outlook and sync to my devices. If I change that it will be because I own the server (not Google/yahoo/Hotmail.) I don't see the need to do that at this time. And I really don't see the need to run exchnage right now so I can add money to my monthly fee. It's about "preference"... one is not better than the other - but the smartphone that wins gives you the choice.
It's a fun OS - I will keep it. But to do so I will have to manually enter in the contacts/calendar and continue to update manually. Until there is a comprehensive backup I am not going to enter in much as last night I had to wipe the device to get around an email setup issue. I had to redo all the sync info from Zune. This phone will be "play time"... and it's fun. The BB will still carry the heavy lifting.
But to each his own here... the more choice the better for us the "users."