Let the hive mind of Engadget get that for you.
"I just switched to Sprint from Verizon about three months ago for the Pre. Then I went for the Hero about a week ago. Now, I miss my hardware keyboard and am thinking about switching to the Moment. I am still able to switch back to Verizon if I want and get the Droid when it arrives. Should I just trade up to the Moment when it comes out, see if I like it, and if not switch to the Droid? Or something else entirely? Help!"
No one I know in IT will even consider allowing Android or iPhone anywhere near their Exchange servers. In the real world it is WinMo and BES since they are the only ones managable or secure in any meaningful way. My company has summarily dismissed someone found to connect his iPhone. If he lost the phone the data is essentially public and their remote wipe is a joke.