Watch a slideshow of this test. |Microsoft Exchange 2010 holds challenges, rewards

Here, he checks out a boatload of the most interesting features and upgrades associated with the shipping product and gives a thumbs up or thumbs down on whether Microsoft delivers the goods. (Read Rand Morimoto's blog.)

Exchange 2010: Why I'm Using It to Say Bye-Bye BlackBerry

1. Database Availability Groups (DAG)

Joel says: Thumbs up

Exchange continues to make high-availability simple by creating DAGs, multiple servers cooperating to make a set of Exchange mailboxes highly available through continuous replication and high-availability failover. It's not a simple feature to roll out, but it's a lot simpler than it used to be and doesn't take a PhD in Exchange to use.

2. Local Continuous Replication is Gone.

Joel says: Thumbs down.

If you loved the idea of having two copies of the same Exchange database on the same server in case your cheapo (or expensive) disk crashed, stick with Exchange 2007. As part of the simplification and extension of high availability, local continuous replication bit the dust. Microsoft's answer: Go get another server instead.

3. It's Mac friendly.

Joel says: Thumbs up

Outlook Web App, the renamed-Outlook Web Access, now works well in non-Microsoft browsers and on non-Microsoft platforms. Safari users, for example, get a great experience with Web-based e-mail, calendaring, and contacts.

4. No client needed

Joel says: Thumbs up

If you don't want to pay for Microsoft Office to get Outlook, or if folks are just as happy reading their e-mail through a Web browser, Exchange 2010 is all about that, even down to the sound cues for alerts. That's right, Firefox can now sound like Outlook!

5. Still a few bugs to get ironed out.

Joel says: Thumbs down

It's new, OK, and while Microsoft tells us that thousands of people are using Exchange 2010, some of the new dark corners have a bug or two left in them. Here's one we stumbled across, where Outlook wouldn't let someone read their own mail -- even though Outlook Web App would. Maybe wait for SP1 before giving this to everyone.

6. Bigger, Better. Faster, More

Joel says: Thumbs up, mostly

Exchange 2007 wanted 64-bits, but it could at least be tested on a 32-bit system. No more. Exchange 2010 insists on 64-bits. This makes your life easier in one sense, since everything is 64-bit through and through. But that's as long as you have 64-bit friendly hardware and plenty of memory.