I bought Microsoft's newest version of Office for Mac (2008) on Tuesday and have been using it nonstop ever since. (Check out the CNET review here.) It is snappy, intuitive, and even innovative in some ways. (MyDay, seen at right, is a blessing.) In short, Microsoft has done something very, very right with this product. I recommend it to everyone who needs it.
Entourage is the biggest area where I see improvements. It is soooo fast compared with Office 2004 for Mac. The UI is gorgeous. My favorite improvement, however, is My Day. It's a floating window that shows my upcoming appointments, "To Do" items, and e-mails that I've flagged for action. It's such a simple addition, but I'm already wholly reliant on it.
The product does have some downsides.
It doesn't save into the OpenDocument Format. (Yes, this is a problem for me as I also use NeoOffice, especially for my presentation files.) And it obnoxiously saves into its new Office Open XML format (which you can turn off but which is aggravating all the same since 99.999 percent of the world still uses the old file formats). Also, synchronization to my BlackBerry has died with this upgrade since PocketMac no longer seems to be able to find the Microsoft Sync Services. (A call to Microsoft's help desk made it clear that Microsoft doesn't know how to find them, either.)
In fact, I can't seem to get it to sync with Apple's iCal and Address Book, either (though colleagues of mine have had no issues doing so). A call to Microsoft has them pointing the finger at Apple, and I'm sure Apple will point a finger back when I call them. Why these companies can't use open standards to make integration easier, I don't know.
What I do know is that the upgrade was worth the price. You might ask why I don't use OpenOffice/NeoOffice exclusively, given that I'm an open-source proponent. Answer: I want an all-in-one communications suite, and neither Apple nor the open-source community makes one. Apple forces me to use disparate applications (Address Book, iCal, Mail, etc.). Open-source provides paltry e-mail tools with the same lack of integration between calendaring, tasks, etc.
So I use Microsoft's Office product, and I'm exceptionally happy with Microsoft Office for Mac 2008, in particular because of its improvements to Entourage, its e-mail client. It's an excellent product.