I too am a BlackBerry geek -- since 2004. My seventh! (I hated the Storm – traded up early, then traded up early to get the new Torch.) I started on Verizon Wireless and have found no reason to switch. (The folks at my local store have gone 'above and beyond' more than once for me.)
Like you, my strongest draw to BlackBerry is the BlackBerry Enterprise Server. And from my Experience with the iPad, ActiveSync is just too limited compared to BES -- which seems to duplicate every capability found in MS Outlook.
But I am getting very frustrated with BlackBerry.
When I got my first BlackBerry, I could walk out of the VZW store with a brand-new device, go home and create a BIS account. I could even access this unique account via a Web client. Then I went to the Verizon web page and discovered that I had to create another account/password to see my Verizon Account. Frustrating, but manageable. The next step was to activate my BES account via my employer. That was a piece of cake. For my next several devices, I simply went back to my BIS account to change the PIN and resent the 'service books' to the new device. And I could keep all my critical passwords in the Password Keeper which is part of BES. Sweet!
Since upgrading first to version 6 (and now to version 7) of the BB OS, all of this has become a nightmare!
When you first activate your phone, you have to (first create and then) login to yet another account called a BlackBerry ID. Then it wants to connect it to your login. (Does it want a username or an e-mail address? Which username? Which e-mail address?)
It wouldn't be so bad if you could get to your Password Keeper. But ALAS, until you can activate the device you cannot activate BES and you cannot get to your password keeper. Since you only do this every couple of years or so, no matter what you figure out now, you are starting over again next time because you won't remember what you did.
Making matters worse, every now and then your device will want you to update itself. It knows who you are when the process starts but doesn't warn you that it has forgotten who you are by the time that the update is finished! So here you are again, without access to your Password Keeper -- and the process starts over again. Hopefully, your spouse also has a BB and you both keep all of your stuff in Password Keeper. Otherwise, you are simply hosed!
Next time around (by which time a NEW BB OS will be out), I am going to have to have to think long and hard about staying with BlackBerry. But, before then, I am going to have to find a new password keeper (and transfer everything in there BY HAND) so that I can access all my passwords from multiple devices -- not just my BlackBerry! Sorry BlackBerry.
Now, aren't you sorry you asked?