for those admins migrating from Exchange 2003 to Exchange 2010 like me, the first thing that we probably notice is the huge difference on how exchange tasks are performed in each server. we all got used to how our old friend exchange 2003 integrated with AD so there was no need to use multiple consoles to create AD accounts and enable mailboxes. Everything could be done from the Active Directory Users & Computers console. now Microsoft completely separated exchange attributes to its own console in Exchange 2010, so creating an AD account is done from Active Directory Users & Computers like before, but creating and enabling mailboxes is done from Exchange Management Console, so you need to use both consoles to setup new users.
Many admins claim the reason Microsoft separated Exchange attributes from AD was because putting everything together would make the properties of AD look clutter, others say that it was because Exchange 2010 is very dependent on PowerShell and AD is not, so both systems cannot coexist any longer. whatever was the reason why Microsoft decided to separate both systems, I welcome the change, I think it makes exchange management tasks a lot easier. it takes time to get used to the multiple consoles, but after awhile it becomes a routine.
Another feature that might throw off some admins not used to a command line is the new Microsoft Management Shell. Basically anything that can be done through the GUI in Exchange, it can be done through the shell console, and then some more. I don’t know PowerShell that much, but I like this feature because of the flexibility of scripting and scheduling many repetitive tasks in Exchange.
Another thing that is very noticeable in Exchange 2010 is speed. When using Exchange 2003 I experienced some lag in Outlook many times ( freezes, sync pauses, etc. ) now its been more than two months that I’ve been using Outlook 2007/2010 with Exchange 2010, and I have never experienced such lags. this might be the result of exchange 2010 running in faster SAN disks, but I read somewhere at Microsoft Technet that Microsoft 2010 is 90% faster than Exchange 2003.. that’s a huge difference in speed.
Overall I’m very happy with the experience I have had with Exchange 2010 so far. I’m using Google a lot to learn new ways of doing tasks in Exchange, but I love learning new things, so I see that as an advantage on my side. technology evolves, and we need to evolve with it.