Blackberry Enterprise server questions
Solution 1:
With the new 5.0 version of it and BlackBerry's with 5.0 software it really becomes a very tight tie to the user's mailbox.
Here is a list of all the features of the 5.0 server http://na.blackberry.com/eng/services/server/5/compare.jsp
If your company is one that likes to lock stuff down, you'll be able to do a much better job of that with the BB's. If you run the trial, you can switch the key over to production when you purchase so you don't need to set it up again, the trial also comes with a support ticket which you can use to help with the installation it does seem a little complex but I used it when I setup ours. It's not too complex really, but it has to plug into Exchange so you need to open up permission to the mailboxes for it.
Solution 2:
ActiveSync has proven itself to be very reliable for my Customers. Microsoft is licensing ActiveSync to Apple and Google, so you'll find it in iPhone and Android devices, as well as on Windows Mobile device.
Blackberry Enterprise Server (at least 4.5-- I haven't used 5.0) seems to be overly complex in its "plumbing", and that worries me. ActiveSync is a fairly straightforward ISAPI application, and isn't tremendously complicated.
Personally, I think that Research in Motion's business model re: Blackberry devices communication to RIM servers which, in turn, receive messages from BES inside corporate networks seems silly and greedy to me. When Blackberry devices were little more than glorified pagers and ubiquitous cellular-based Internet connectivity didn't exist that probably made sense. Today, it seems to be nothing more than a way for RIM to siphon money off of both the device users and the IT departments supporting them.
Solution 3:
The company I do IT for uses both WinMo and BB phones. Personally I like MS's implementation of exchange sync better than anything BB can do - not to mention it's $30/mo per phone cheaper.
The only reason we are still using BB's is the need for Sprint's Direct Connect (not a problem for you), BB messaging, and the way BBs work internationally. If all you need is domestic exchange integration, by all means use windows mobile. HTC's Touch Pro and Touch Pro 2 erase a lot of the down sides of Windows Mobile with their Touchflo 3D.