I'm on 2010, and I was previously on 2007, and 2003, and... And, I tried Thunderbird last week, for 1 week (before I joined the 2010 beta). All I can say about Thunderbird is this: What the fuck?! No, really, what the fuck?! Yeah, it's free. But, it is the biggest piece of shit of a mail client out there today. Any company that let's its staff use something like that is losing about 3 hours a day in productivity. So, my vote: MS Office 2010. The 'Click-to-Run' way of doing business was a long time coming and completely practical. And, the new Office blows 2007 out of the water in every category, including speed, and, of course, makes Thunderbird look like a joke (there is a $300-500 price difference between the two for a reason). Stand by for a full review in a couple of weeks, I'll definitely post one once I've had the opportunity to spend some more time with it.
