IT Pro Verdict
Judging Outlook is tricky. If Entourage had never existed, it would be an amazing product. However, compared to Entourage it leaves out a few key features while gaining better Exchange support. Overall, if you’re an Exchange user, and your company uses a compatible Exchange server, it’s worth upgrading immediately. If you don’t use Exchange, though, you may want to hang on to your copy of Entourage a little while longer.
It's arguable that Entourage, the personal information management and email application introduced with Office 2001 for Mac, was superior to Outlook, it's Windows counterpart. Not only did Entourage look better than Outlook, but it had features like a Projects section that Outlook lacked.
With Office 2011, Microsoft has taken the opportunity to rethink Entourage, and has effectively binned it for a new, ground-up rewrite which it has named Outlook. Why? Because unlike Entourage, Outlook focuses much more heavily on connectivity with Exchange servers. It is still a more-than capable POP and IMAP client, but Exchange users will get the most out of the new application.
That rewrite is more than just cosmetic. Microsoft has taken the opportunity to use Cocoa, rather than Carbon, as the key API. This is sensible, given Apple's general indication that Cocoa is the future of Mac programming, and it also allows Microsoft to take advantage of new Mac OS X technologies more easily in the future.
Outlook doesn't completely abandon everything from Entourage. For example, the Mailing List Manager and Rules system are essentially unchanged. This is good, as both are excellent features. But almost everything else has changed, and some features notably the Projects feature in Entourage, which let you group together related contacts, tasks, meetings and mail messages, is gone.
The overall look and feel of Outlook is more consistent with the Windows version, and adopts the context-sensitive Ribbon that's now common across both Mac and Windows versions of Office. The Ribbon is the Marmite of the software world you either love it or hate it. Personally, we find it a relief from the old style of toolbar-mania. Even if you disagree at first, it's worth giving it a chance.
